Vowel Categorization Skill and Its Relationship to Early Literacy Skills among First-Grade Québec-French Children

Journal of Experimental Child Psychology 76, 190 –221 (2000) doi:10.1006/jecp.1999.2547, available online at http://www.idealibrary.com on

Vowel Categorization Skill and Its Relationship to Early Literacy Skills among First-Grade Que´bec-French Children Marke´ta Caravolas McGill University, Montreal, Quebec, Canada

and Maggie Bruck Johns Hopkins University Six-year-old children’s ability to categorize words on the basis of vowel categories was examined at the beginning of first grade and again after 6 months of formal schooling. The potential effects of relative proximity of vowels in the vowel space, of syllable structure, and of input phonology were assessed. Also, the effect of literacy instruction on vowel categorization and the relationship of vowel categorization with vowel spelling and reading skill were investigated. Results indicate that the ability to categorize vowels does not develop uniformly but is affected by the degree of spectral/articulatory proximity between vowels, by syllable structure, and potentially by characteristics of the input phonology. Error analyses further indicate that children have fuzzy category boundaries between vowels adjacent on the height continuum. The pattern of results on oral categorization and written tasks suggests a reciprocal relationship. Categorization ability improved after 6 months of schooling. However, vowels that children found more difficult to categorize were also more difficult to read and spell. © 2000 Academic Press Key Words: vowels; phonology; phoneme awareness; reading; spelling; categorization.

Although a great deal is known about the development of phonological awareness in preschool and early-school-aged children, and about its critical role in the acquisition of alphabetic literacy, relatively little is known about children’s awareness and representation of specific classes of phonemes. The existing research has focused on the definition and delineation of the types of phonological manipulations that children are able to perform and on the developmental This research was supported by a grant from the FCAR to the first author and by a grant from the Natural Sciences and Engineering Research Council to the second author. Thanks to Danielle Gallipeau for her help in testing participants and thanks to the teachers and children who participated. Address correspondence and reprint requests to Marke´ta Caravolas, Department of Psychology, University of Liverpool, Eleanor Rathbone Building, Bedford Street South, Liverpool, L69 7ZA, United Kingdom. E-mail: [email protected]. 190 0022-0965/00 $35.00 Copyright © 2000 by Academic Press All rights of reproduction in any form reserved.

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patterns of performance on various tasks (e.g., Stahl & Murray, 1994; Stanovich, Cunningham, & Cramer, 1984; Yopp, 1988). Other research demonstrates that preschoolers’ awareness of sublexical phonological units such as rimes and onsets is a strong determinant of later reading/spelling success, and in turn, formal literacy instruction raises children’s awareness of phonological units (Bryant, MacLean, Bradley, & Crossland, 1990; Perfetti, Beck, Bell, & Hughes, 1987). Children’s phonological/phonemic representations have been examined indirectly in research on prereaders’ and early readers’ spelling. Both Read (1975, 1986) and Treiman (1993) suggest that some spelling errors reflect young children’s phonological representations, which differ from those of adults. Specifically, young children internalize the surface phonetic aspects of speech input and therefore their representations differ from formal phonological descriptions. For example, beginning spellers frequently omit postvocalic nasal graphemes; they spell “bent” as bet. Treiman, Zukowski, and Richmond-Welty (1995) found that beginning spellers who made such systematic errors also tended to count the vowel and ensuing nasal as a single segment on a phoneme counting task (i.e., they segmented “bent” as /b/–/␧n/–/t/). It is argued that these data reflect young children’s representation of the nasal segment as a phonetic attribute of the vowel. Because English does not contain nasal vowel graphemes to represent these “nasalized vowels,” it is assumed that children select the closest corresponding oral vowel grapheme. Other examples of phonologically motivated spelling errors include the omission of vowels adjacent to the syllabic liquids, /r/ and /l/ (Treiman, Berch, Tincoff, & Weatherston, 1993), and the misspelling of flapped /t/ ([ɾ]) phonemes as d (Ehri & Wilce, 1986; Treiman, Cassar, & Zukowski, 1994). In these same studies, children’s spellings of specific phonological units correlated with their ability to manipulate the target units on oral phonological awareness tasks. The above studies provide compelling evidence that children’s performance on phonological awareness tasks and on spelling tasks is partly determined by their underlying representations of specific phonemes in specific word positions. However, these investigations have been limited to the study of consonants. In the present study, we investigated children’s representation and awareness of vowel categories. For several reasons, the development of phonemic representations and of explicit awareness for vowels may be influenced by factors that are less relevant to the development of consonants. Vowels are the essential constituents of syllables and they are the main carriers of prosodic information; in contrast, consonants are not essential syllabic constituents and they tend to carry morphological information. Compared to consonants, vowels are more susceptible to variation caused by variables such as speech rate, vocal tract size, lexical stress, syllable structure, consonantal context, and dialect (House & Fairbanks, 1953; Kuhl, 1987; Ladefoged & Broadbent, 1957; Van Bergem, 1993). Perceptually,

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vowels have less discrete category boundaries and have acoustic properties that are more conducive to continuous (noncategorical) perception than consonants (Pisoni, 1973; Sawusch, Nusbaum, & Schwab, 1980; Studdert-Kennedy, 1993). Surprisingly, there is little research on the formation of perceptual categories for vowels in children beyond the age of infancy. For example, Kuhl (1979, 1983; also Marean, Werner, & Kuhl, 1992) found that 2- to 6-month-old infants ignore acoustic differences due to speaker, gender, and intonation in vowel tokens and that they discriminate vowels based on categorical membership. However, infants accomplish these fine-grained categorical discriminations on the basis of prelexical, phonetic processing (Kuhl, 1993; Werker & Desjardins, 1995), not on the basis of phonological knowledge. Thus, what is true of the abilities of 6-month-old infants may not be true of the lexically based abilities of older children. The sparse data on developing vowel phonology in older children come primarily from studies of invented spelling (Read, 1971, 1974, 1975; Treiman, 1993). Typical patterns of vowel misspellings suggest that young children have underspecified representations of certain vowel features. The most prevalent and best documented error type suggests an underspecification of the height feature for front vowels. That is, children frequently spell words containing the lax vowel / / with the letter e (e.g., “milk” as melk, “fish” as fesh) and lax /␧/ with the letter a and sometimes with i (e.g., “bell” as bal, “went” as wint). Children rarely misspell words containing / / and /␧/ with letters such as u or o, which represent vowels in the back portion of the vowel space. The above misspellings may be motivated by other phonological factors. For example, Read (1975) and Treiman (1993) proposed that children who use letter names to spell might spell “milk” as melk because the letter name of e (/i/) is similar to the lax vowel / /. Alternatively, factors such as coarticulation from the ensuing consonant or dialect-specific pronunciations of vowels may influence children’s vowel spellings. Although the extent to which each of these factors affects children’s developing vowel representations is yet to be examined experimentally, the underspecification hypothesis is supported in a study by Ehri, Wilce, and Taylor (1987). In order to appreciate the phonological motivation of the study, some facts about English vowel phonology are first outlined. As shown in Fig. 1, all English vowel phonemes can be characterized in terms of articulatory features such as tongue height, tongue frontness/backness, lip rounding, tongue root advancement (tenseness/laxness), and segmental complexity (i.e., monophthong or a diphthong). For example, the / / in “pick” is a high, front, unrounded, lax monophthong whereas the vowel /␧/ in “peck” is a low– mid, front, unrounded, lax monophthong. Thus, if the height feature is not fully integrated in children’s vowel representations, they should frequently confuse / /, /␧/, and /æ/ as these vowels share the phonetic features for frontness, rounding, and laxness but differ on the height feature. This is the pattern of vowel misspellings reported by Treiman (1993) and Read (1971, 1974). Front, lax

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FIG. 1. Schematic of English monophthong vowel positions on the height and backness dimensions.

vowels are the only class of vowels that have been examined on oral as well as spelling tasks. Ehri et al. asked first graders (Experiment 1) and second graders (Experiments 1 and 2) to categorize the vowels of picture words containing / /, /␧/, or /æ/. Children first learned to associate pictures of three target characters with names that contained one of the three vowels (e.g., Bitty, / /; Betty, /␧/; and Batty, /æ/, Experiment 2). Next, they were asked to name pictures depicting monosyllabic words containing one of the target vowels (e.g., “pal,” “web,” “fish”). On the basis of their own pronunciations and vowel extractions from the picture names, they placed the picture with the target character that shared its vowel (e.g., “pal” goes with Batty). Ehri et al. (1987) hypothesized that if children’s frequent confusions of front lax vowels arise because they are articulated similarly, then children would more frequently miscategorize vowels that are closer on the height continuum than vowels that are further apart on the continuum. Thus, children should more frequently miscategorize / / words to the nearest neighbor, /␧/, than to the farther neighbor /æ/, and they should miscategorize /␧/ words equally frequently to / / and /æ/ as both vowels are immediate vowel space neighbors to /␧/. This pattern of miscategorization errors was obtained (Experiment 2). There was also an unexpected effect of coarticulation on categorization performance, whereby children tended to raise vowels (i.e., miscategorize them to higher neighbors) that were followed by velar and nasal consonants. Thus the results from two different paradigms (spelling and oral categorization) support Treiman’s (1993) claim that children’s vowel representations even at 7 years of age are still closely related to the surface features of their own lexical pronunciations. Ehri and her colleagues also found that phonemic categories do not develop at equal rates for all vowels. Namely, children consistently categorized /␧/ words less accurately than words containing the other two vowel types. This finding is also consistent with the articulatory similarity hypothesis because /␧/ has two immediate neighbors whereas the other two vowels have only one; nevertheless,

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Schematic of Que´bec-French vowel positions on the height and backness dimensions.

it is not known if articulatory similarity accounts for all variation in vowel category development. Finally, Ehri et al. found a direct effect of spelling knowledge on children’s explicit phoneme representations. Children who were better readers (Experiment 1) and who learned specific vowel spellings in to-be-categorized words (Experiment 2) performed significantly better than poor readers and children who had not learned specific vowel spellings. In the present study we adapted and extended Ehri’s paradigm to examine vowel categorization skills in children speaking a language other than English. The sorting task of Ehri et al. (1987) was employed with Que´bec-Frenchspeaking children in Grade 1. Testing speakers of Que´bec French permitted a crosslinguistic comparison to published research on English-speaking children as well as an examination of the role of some phonological factors that are present in the complex vowel system of Que´bec French. Some Facts about Que´bec-French Vowel Phonology We now outline the characteristics of Que´bec French that are relevant to the present study. (The vowel system, along with a phonetic key, is described in fuller detail in Appendix A.) First, this French dialect has a complex vowel system with a large inventory of 16 monophthong vowels—12 oral and 4 nasal (see Fig. 2). Among the world’s languages, this represents a rather crowded vowel space. Thus, it is of interest to investigate the accuracy of preliterate children’s explicit category judgments in a language with many vowel categories. Second, Que´bec French has a four-tier division on the height continuum and three sets of vowels fall on this continuum: front-unrounded vowels, frontrounded vowels, and back vowels. We examined children’s ability to discriminate and categorize vowels in the front-unrounded (henceforth referred to as front vowels) and in the back set. Third, in Que´bec French there is a tendency to reduce articulatory stress and tension by means of laxing and diphthongization of vowels (Dumas, 1987). This process operates mainly in closed syllables that are naturally heavy and contain long and tense vowels. Laxing and diphthongization

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produce a general tendency in Que´bec French to vowel lowering. An important implication of these processes for the language learner is that they give rise to a considerable amount of allophonic variation; a single vowel can have multiple realizations depending on its syllabic and consonantal context. For example, the vowel /i/ may be realized as [i] in [sci] (“scie”), as [ ] in [p p] (“pipe”), and as [e i] in [tze i ] (“tire”). In order to acquire a fully functional vowel system, the Que´bec-French-speaking child must presumably learn to correctly interpret the diverse sources of allophonic variation and to map the phonetic variants to their appropriate phoneme categories. Que´bec French is not unique in this respect, but it does contain less stability and more allophonic variation in vowels than Standard European French, for example (Charbonneu, 1971). Thus it is of interest to document whether such surface phonetic variations influence the formation of vowel categories and when in development children recognize the allophones as members of their appropriate vowel categories. The Present Study Five questions about phonemic awareness and representation of vowels were addressed. First, are children’s difficulties with distinguishing vowels along the height dimension universal? Using the task designed by Ehri et al. (1987) we investigated whether speakers of Que´bec French perform like their American-English counterparts on a comparable set of front vowels (/i/, /␧/, /a/). 1 This issue was raised because increasing evidence suggests that language-specific as well as dialect-specific phonological input affects not only developmental patterns and The Que´bec-French vowel set /i, ␧, a/ compares with the American-English front vowels / , ␧, æ/ as follows. In Que´bec French, [ ] is an allophone of the category /i/. The phone [i] occurs primarily in CV words and word-internally in strong open syllables. As in English, the phone [ ] occurs in CVC contexts such as “pipe” [p p] and “dix” [dz s] and in weak (CV) word-internal syllables such as “pilule” [p 1 1]. However, when followed by certain “lengthening consonants” such as /r/, /v/, and /Z/, the vowel /i/ necessarily lengthens and may diphthongize to variants such as [ i] or [e i] (e.g., “tire” [/tir/ becomes [tz i ] or [tze i ]). The Que´bec-French vowel /␧/ occurs in CV as well as in CVC short syllables. In closed syllables ending in lengthening consonants, it diphthongizes most typically to [a ␧], and in certain word- and speaker-specific cases, to [e i]. Although some Que´becFrench phonologists categorize the long variant of /␧/ as a distinct phoneme, it was, according to Dumas’s (1987) interpretation, treated as a diphthongized allophone of /␧/ in the present study. The Que´bec-French low vowel equivalent for the English /æ/ is /a/, which is, in fact, defined as a central and not a front vowel. It was included nevertheless, because it is the closest relative of the English /æ/, sharing with it the features of labialization (i.e., unrounded) and height (i.e., low). Moreover, in Que´bec French its typical articulation occurs in front of the center of the vowel space (Charbonneau, 1971; Delattre, 1957). Because neither language contrasts /æ/ and /a/, the two vowels may be considered as variants of the archphoneme /A/ (Delattre, 1965). It is evident that narrow phonetic comparisons with Ehri et al.’s vowel stimuli are not possible; the phonemes are drawn from two languages, after all. Importantly, however, the commonalities between the Que´bec-French vowels and their American-English counterparts are sufficient to permit the study of a number of questions raised in studies with American Anglophone children. For the sake of simplicity, the Que´bec-French set /i, ␧, a/ will be referred to here as the front-vowel set. 1

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rates of phonological awareness (Bruck, Genesee, & Caravolas, 1997; Caravolas & Bruck, 1993; Cossu, Shankweiler, Liberman, Katz, & Tola, 1988; Mann, 1986) but also children’s developing phonemic representations (Treiman, Goswami, Tincoff, & Leevers, 1997). Second, do other characteristics of vowel phonology, such as the spectral proximity of vowels, influence the development of vowel categories? A nonhigh, back vowel set, /ɑ/, /ɔ/, /o/, (henceforth referred to as the back vowel set) was included for this purpose (see Fig. 2). Like the front set, the back vowel set lies on the height continuum. However, these three vowels are typically realized in greater spectral (acoustic)— hence also articulatory—proximity to one another than are the three front vowels. In fact, the first and second formant frequencies of the vowels /ɑ/ and /ɔ/ frequently overlap (Charbonneau, 1971), and in Que´bec French, these two vowels may be completely homophonous in certain contexts. Importantly, however, /ɑ/, /ɔ/, and /o/ differ from each other in terms of two articulatory features (/ɑ/ and /ɔ/ differ in height and rounding; /ɔ/ and /o/ differ in tenseness and by extension in height). In contrast, with the exception of /i/ in open syllables, the Que´bec-French /i/, /␧/, and /ɑ/ differ on the height dimension only. Thus, the back vowel set permitted an examination of children’s categorization ability with vowels that are acoustically/phonetically more proximal but underlyingly more distinct than the front vowels. Importantly, children might perform this task with no particular difficulty if they attend to the various sorts of evidence in speech input which indicate more clearly the difference between the vowel pair /ɑ/ and /ɔ/. Such evidence is provided in Standard Que´bec French—the tenser, nondiphthongized form mainly used in the media—in which words such as “part” and “port,” for example, are pronounced [pa ]/[pa ] and [pɔ ], respectively. Also, children with greater linguistic sophistication may implicitly derive knowledge about vowel phoneme identities on the basis of morphologically related words such as “part” [pɑ ɔ ] and the related form “partir” [paRtiR], or “fort” [fɑ ɔ ] and its relatives “force” [fɔ s] and “forcer” [fɔ se]. If young children do not use these clues, and if, in addition, spectral proximity plays a role in the development of vowel phoneme representations, then Que´becFrench children may categorize the back-vowel set more poorly than the front set, despite the fact that the set is more dissimilar in terms of underlying features than the front set. Third, to what extent are the phonemic representations of school beginners influenced by allophonic variation brought about by syllable structure? Although Ehri et al. (1987) and Treiman (1993) observed that children’s vowel representations were influenced by the postvocalic consonant context (be it general articulatory or dialect-specific), the more general effect of syllable structure was not examined. According to most accounts of phonological development (Branchu, 1971; Juszyk, 1986; Oller & Steffens, 1994), children’s ability to access, and perhaps represent, the phonemic structure of open syllables should precede that of closed syllables because CVs emerge earlier and are more frequent in infant

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speech production than CVCs (Kent & Bauer, 1985; Oller, 1986), and because children demonstrate earlier articulatory control over speech sounds in CV syllables than over those in larger units (Kent, 1992). In the present study, if Que´bec-French-speaking children are better able to categorize vowels in open syllables than in closed syllables, this might mean that their vocalic representations are not independent of syllabic context, and that within closed syllables, their vowel representations are less well defined. This problem may be compounded in Que´bec French by the stress reduction processes of laxing and diphthongization in closed syllables. If these dialect-specific processes have a negative effect on children’s vowel representations, then those vowels that undergo the most radical timbre changes should be most poorly categorized. In the case of the front vowels, CVC-embedded /i/ and /␧/ should be less well categorized than /ɑ/ because the former are subject to greater phonetic variation than the latter. In the back-vowel set, effects of allophonic variation should lead to poorer categorizations of /ɑ/ and /ɔ/, which are frequently interchangeable, and best performance on /o/, which has a relatively stable pronunciation. Fourth, do children’s misclassification patterns reflect fuzzy category boundaries? In the case of Que´bec French (and perhaps in all languages) a fuzzy boundary effect should be more evident in CVC syllables, where more factors conspire to bring about allophonic variation and, presumably, ambiguity in the vowel’s identity. If the stress reducing process of Que´bec French specifically affects vowel category development, children should show the strongest fuzzy boundary effects between vowel categories which are approximated in laxing and diphthongization. For example, children should more often miscategorize /␧/ as /a/ because /␧/ often diphthongizes toward /ɑ/, but they should rarely miscategorize /␧/ as /i/ because diphthongization toward /i/ is much less frequent in Que´bec French (Dumas, 1987). In the back set, fuzzy boundaries should be demonstrated between /ɑ/ and /ɔ/, which are not only very close in the vowel space, but are sometimes completely homophonous. Finally, because /o/ does not diphthongize downward to /ɔ/ (but rather raises toward /u/), the boundaries between these two vowels might be better established. Fifth, what is the association between formal letter-sound instruction and vowel categorization ability? The vowel sorting tasks were administered at the beginning of Grade 1 prior to any formal literacy instruction and again 6 months later, at which time the grapheme–phoneme correspondences for these vowels has been formally taught. Thus an improvement in categorization over time would reflect the effects of literacy instruction on the phonemic awareness of vowels. It is also possible that improvements over time could reflect general developmental factors. However, given the well-documented impact of literacy on phonological awareness development (Adria´n, Alegria, & Morais, 1995; Ehri et al., 1987; Perfetti et al., 1987), it is likely that gains on the vowel categorization tasks would be related to the acquisition of literacy skills. Also, in order to examine the influence of vowel categorization ability on the development of

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literacy skills, spelling and reading tests were administered at the second testing. Because each literacy task contained a subset of the words that the children had categorized, we could directly assess the relationship between phonemic awareness of specific classes of vowel phonemes and the ability to represent them in print. METHOD Participants Twenty-one normally developing children, all monolingual speakers of colloquial Que´bec French, with a mean age of 6 years (range 5.8 years to 6.11 years) participated in this study. The participants attended one of two neighboring schools in a suburban middle-class area of Montreal. A selection criterion required that the children be nonreaders at the start of testing (see below). Language Background Native Que´bec Francophones all speak a dialect which is referred to as Que´bec French. There is also a standard dialect which closely resembles Standard European French. This standard form is mainly used in the media and is rarely used informally in the home and school setting; thus in the present study the standard dialect was not the child’s input dialect. In order to confirm that all participants in the present study were Que´bec-French speakers, parents completed a questionnaire which included items regarding the mother tongue of both parents, the place of birth, and the speech and hearing development of the child. All selected participants were born in Que´bec to at least one native Que´becois parent and French was the only language spoken in their home. Also, during the initial screening session, the children’s speech was evaluated for the presence of three basic phonetic features of Que´bec French. 2 The features were present in all of the children’s speech. School Setting The children’s teachers were all native speakers of Que´bec French. That is, their normal speech contained vowel laxing and diphthongization. Both schools used the same phonics-based method of reading instruction in which children were taught to blend letters into simple syllables, and syllables into words. Grapheme–phoneme correspondences were explicitly taught but phonemic awareness was not. When individual sounds were taught, the teachers presented all vowels as tense monophthongs (with the exception of true diphthongs). Thus although the normal language in the classroom was typical Que´bec French (in terms of vowel phonology), the sound–symbol correspondences were taught 2

Specifically, children’s speech was analyzed for the presence of affrication of /t/ and /d/ when followed by /y/ and /i/ as well as high vowel laxing (e.g., /ty/ 3 [tz ], /di/ 3 [dz ]), homophonous pronunciation of /ɑ/ and /ɔ/ in certain words (e.g., /pɑt/ 3 [pɑ ɔt]; /fɔR/ 3 [fɑ ɔR]), and generally diphthongized speech.

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according to standard Que´bec-French pronunciation. At the time of retest (March, April) all monophthong vowel– grapheme correspondences had been taught. Although no standardized test of word recognition was administered at retest, the results of the 66-item word and nonword reading tests suggested that these children were decoding fairly well (75% accuracy on words and 71% on nonwords). As part of their spelling program, children were taught to write the letters and syllables taught in reading. Also, each week, children learned short word lists that contained words which shared phonological and spelling patterns as well as high-frequency words encountered during the week’s lessons. Testing Schedule The children were tested at two time periods. The first (Time 1) took place in September/October and involved four sessions of approximately 20 min each. The second test period (Time 2) took place in March/April and involved four sessions of approximately 15 min each. Tasks Reading Screening Task At Time 1, children were asked to read 10 primer words, presented individually in lowercase, 36-point font. Children who correctly read more than 3 words were excluded from further testing. Four children were excluded from further testing, for a total sample size of 21 children. Vocabulary The EVIP, a measure of receptive vocabulary (Dunn, The´riault-Whalen, & Dunn, 1993), is the standardized French version of the Peabody Picture Vocabulary test. Using the published guidelines, the test was administered to each child individually, at Time 1 only. The group standard mean on this test was 125 (SD ⫽ 18), with a range in standard scores from 85 to 153 points. Letter Knowledge Children were shown cards with individual, lowercase letters. They were asked to name each letter and then to say the sound or sounds made by that letter. The Letter Knowledge Task was administered immediately after the EVIP at Time 1, and during the first testing session at Time 2. At Time 1, the mean score for Letter Names was 15.3 (SD ⫽ 8) out of a possible 26 (range 4 –26). The mean score for Letter Sounds was 4.5 (SD ⫽ 6) out of a possible maximum of 28 (range 0 –23; modal score ⫽ 0). Thus, although these children were well within a normal verbal IQ range, they were nonreaders, and their preliteracy skills, as measured by knowledge of Letter Names and Letter Sounds, were quite limited. At Time 2, the mean scores for Letter Names and Sounds were M ⫽ 25.6 (SD ⫽ 0.5) and M ⫽ 24.3 (SD ⫽ 4), respectively.

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Vowel Categorization Tasks The procedures developed by Ehri et al. (1987) were adapted for the present study. Whereas Ehri et al. examined children’s categorization of only one set of vowel contrasts, we separately examined children’s categorizations of two different sets of vowel contrasts. Stimulus Set 1: front vowels. The first set contrasted the vowels /i/, /␧/, and /a/. Three target pictures depicted drawings of giraffes named “Riri” [riri], “Raieraie” [r␧r␧], and “Rara” [rara]. Each giraffe was named according to her “favorite thing,” which was also demonstrated in the drawing. For example, Riri loved to laugh (“rire” in French), Raieraie loved stripes (“les raies” in French), and Rara loved rats (“les rats” in French). The syllable reduplication in each name was intended to provide each vowel sound in the word-internal as well as word-final positions. The target names were taught to the child until he or she could name each character unaided. The sorting pictures included 12 /i/, 12 /␧/, and 12 /ɑ/ words. For each vowel type, there were 4 CV words containing short and nondiphthongized vowels (e.g., “scie” [Si], “lait” [l␧], “chat” [兰a/), 3 4 CVC words containing short, lax vowels (e.g., “pipe” [pIp], “pelle” [p␧l], “balle” [bal]), and 4 CVC words containing lengthened vowels (e.g., “tire” [tzi r], “neige” [n␧ Z], “lave” [la v]). Short and long variants were included in order to have a representative sample of the types of vowel sounds that children hear in the CVC context. Stimulus Set 2: back vowels. The second set contrasted the vowels /ɑ/, /ɔ/, and /o/. The vowels were presented in CVC words only because /ɑ/ and /ɔ/ do not occur in open, word-final syllables or in open monosyllables (Dumas, 1987). Three target pictures depicted drawings of rabbits named “Paˆmepaˆme” [pampam], “Pommepomme” [pɔmpɔm], and “Paumepaume” [pompom]; each was depicted with its favorite thing or main characteristic. Thus Paˆmepaˆme was smitten with carrots (“se paˆmer” in French), Pommepomme loved apples (“les pommes” in French), and Paumepaume loved his big, pink palms (“les paumes” in French). The sorting items consisted of 27 pictures: 9 in the /ɑ/ category (e.g., “paˆte” [pɑt]), 9 in the /o/ category (e.g., “saute” [sot]), and 9 in the /ɔ/ category (e.g., “dort” [dɔr]). Length was not varied in the /ɑ/ and /o/ categories because this distinction does not occur in CVC words. Among the /ɔ/ items, 5 contained long vowel variants (e.g., “dort”) and 4 contained short vowel variants (e.g., “robe”). The full list of words for each set is in Appendix B. Although an attempt was made to have as many items as possible representing each vowel and syllable condition, the children’s attentional limitations, on the one hand, and the practical matter of finding enough suitable words, on the other, determined the actual set sizes. The two vowel sets were analyzed separately, and therefore, it was not essential to have an equal number of items in each set. 3

French vowels in open syllables are always short monophthongs.

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Procedure. Each child was given a stack of 36 (Set 1) or 27 (Set 2) pictures of common objects or concepts. The experimenter asked the child to name each picture. When a child used a word other than the one intended or when the picture failed to elicit a label, the experimenter prompted the child with leading sentences. For example, to elicit the word “rich” (“riche” in French) the experimenter said (in French): “This man has a lot of money, he is _”. When semantic cues of this sort were not effective, the experimenter provided the first consonant of the word (e.g., “rrr”); if this cue also failed, she pronounced the word herself and asked the child to repeat it. The card was then set aside and was retested at the end of the picture naming procedure. Thus, prior to the start of each categorization set, the children had learned the appropriate label for each picture. The children were next introduced to the three target pictures and their names. They were told to pronounce each picture name and to listen to its middle sound; they were then asked to pronounce the picture name followed by the name of each target animal. For example, having said the word “chat,” they were to say “chat”–“Riri,” “chat”–“Raieraie,” and “chat”–“Rara” and then to place the card under the animal which shared its middle sound. In Set 1, six demonstration trials ensued; the first three (one for each target vowel) were performed by the experimenter, the remaining three by the child with corrective feedback when necessary. Corrective feedback entailed having the child focus on the vowel sound of the picture word and modeling for her the correct response. The demonstration items were not re-presented during the test phase. In Set 2, only three practice trials, performed by the child with corrective feedback, were presented because it was difficult to find a sufficient number of imageable, age-appropriate words. Following the practice trials, the test began. Note that an important component of the task was that the children sorted the pictures according to their own pronunciations of the depicted words. Hence, their categorizations were not shaped or biased by the pronunciation of the experimenter. Each set was administered on a separate day over the course of a 3-week testing period at Time 1 and again at Time 2. At Time 1 the administration of each set took approximately 20 min; at Time 2 most children completed the tasks in approximately 10 min. At Time 1 Set 1 was administered prior to Set 2; at Time 2 the order of the Sets was counterbalanced. Spelling Task Stimuli. A spelling task was administered at the end of the Time 2 session. At this point, the children had received 6 months of explicit instruction in phonics and spelling. The children were required to spell 58 words on the basis of their own word productions, which were generated from a set of pictures representing monosyllabic words. In the present study, a subset of 26 of the 58 test words was analyzed; these 26 words had also been used in the two vowel categorization sets. These were 18 words from the front vowel set (6 from each vowel type, sampling

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evenly across syllable type, and duration type in CVC syllables) and 8 words from the back vowel set (2 from the /ɑ/ and /o/ categories, and 4 —2 short and 2 long—from the /ɔ/ category). The complete list of these words is presented in Appendix B. Procedure. Each child received a booklet containing pictures of the words to be spelled. These same pictures were used in the vowel categorization task. For each word, the child was instructed to name the picture and to spell the word. Beneath each picture, the article (i.e., gender determinant)—when appropriate— and the first consonant(s) were printed in lowercase. For example, below the picture of a glove (“gant” in French) was le g_. The child’s task was to complete the spelling with the appropriate vowel (and consonants for CVC words). The task was administered to small groups of three or four children. Two experimenters monitored the children’s progress during the task and elicited the correct word in cases where children appeared unsure or were attempting to spell a word other than the one targeted by the picture. Experimenter intervention was rare because the children had previously named these same pictures in the categorization task. Scoring. There were two measures of the children’s written representation of the vowel. First, each vowel spelling was evaluated for correctness according to the conventional spelling. Thus there was only one possible correct vowel spelling for each word. One point was awarded for each correct spelling. Second, vowel spellings were scored in terms of their phonological acceptability. A phonologically acceptable spelling was one in which the vowel was represented by a plausible grapheme, although the grapheme need not be the conventional one, nor orthographically legal in the particular word context. For example, the spelling pe` for the word “paix” was phonologically acceptable because the grapheme e` can represent the phoneme /␧/ in French. On the other hand, the spelling pe´e for the word “paix” was not phonologically acceptable because e´e never represents /␧/. 4 Further examples of acceptable and unacceptable spellings are provided in Appendix B. Word Reading Task Stimuli. Children read a list of 66 monosyllabic words with regular orthographic patterns (22 open syllable, 44 closed syllable) at Time 2. Their performance on a subset of 31 words corresponding to the depicted items of the categorization tasks was evaluated in the present study: 20 words from Set 1 and 11 words from Set 2 (see Appendix B). Mean word frequency was 107 (SD ⫽ 142) occurrences per million (range: 2 to 588). The frequencies were obtained in Baudot’s (1992) index, which is fashioned after Kuc˘era and Francis (1967) and is based on a corpus of over 1 million words obtained from printed text of French and French-Canadian origin. 4

Note that whereas the /e/–/␧/ contrast has virtually disappeared in European French, it is still maintained in Que´bec French (Dumas, 1987; Walker, 1984).

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Procedure. The words were printed in lowercase (14-point font size) in two columns on two sheets of paper. Each child was asked to read aloud the words on the list. A cardboard sheet was used to cover words the child had yet to read; thus as each child read, he or she saw one word at a time. When children decoded a word with difficulty, they were asked to repeat the word in order to determine if they recognized it. Children’s self-corrections (even if these occurred after two decoding attempts) were counted as correct. Children who produced an incorrect reading more than three times and then produced the correct one were considered to have difficulty with that item and were not awarded a point. Children were encouraged to try to read all of the words. No corrective feedback was given. The reading session was audiotaped. These recordings were used to score the test. In addition the experimenter transcribed the children’s responses as they read the words; these transcriptions were used to confirm any ambiguous reading productions. In general, however, the children’s recorded articulations were very intelligible. The children were tested individually following the administration of their last categorization task. The task took 10 –15 min to administer. Scoring. The reading evaluation focused on the accuracy of the vowel reading only. Children were awarded a point if they pronounced the correct vowel sound regardless of the correctness of the whole word reading. For example, a child who read “loup” (conventionally pronounced [lu]) as [lupə] was awarded 1 point for vowel accuracy, although he or she misread the word as a whole. Nonword Reading Task Stimuli. Sixty-six nonwords (22 open syllable, 44 closed syllable) were created by changing the first consonant of each word in the Word Reading Test. The ensuing vowel and consonants were identical to those of the original real words. For example, the word “sac” became the nonword “rac” and “port” became “vort.” As each nonword was derived from a real word on the Word Reading Task (which in turn contained words from the vowel categorization task), it was possible to examine the relationship between vowel reading in nonwords which corresponded to real-word counterparts from the categorization task. Twenty items corresponded to words from Set 1, and 11 to words from Set 2 (see Appendix B). These 31 nonwords were specifically analyzed in the present study. Procedure. The Nonword Reading Task was administered exactly as the Word Reading Task except that children were told they would read invented words. Scoring. Only the accuracy of the vowel reading was scored. Any plausible vowel production which could occur in the given phonemic context in a real French word was considered correct. For example, for the nonword “teine” (derived from the word “reine”), the production of a short [␧] as in [t␧n] and the production of a long [␧:] as in [t␧:n] were both scored as correct because the digraph ei can represent both the short (e.g., “peine”) and the long (e.g., “reine”) variants in that context. On the other hand the production of [o] in the word “vort” (derived from the word “dort” [dɔ:r]) was considered incorrect because in

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French, /o/ does not occur before syllable-final /r/; in this case the correct vowel is /ɔ/ and the correct reading of “vort” is [vɔ:r]. This contextually constrained scoring method was preferred over a completely unconstrained scoring method, in which any plausible reading of a vowel or consonant grapheme was accepted, because it is a more sensitive measure of children’s phonological sophistication (see Bruck, Treiman, Caravolas, Genesee, & Cassar, 1998; Bruck & Waters, 1988). It should be noted that, compared to those in English, the grapheme-to-phoneme mappings for French vowels are fairly transparent. Consequently, within the positional and sequencing constraints of the orthography most of the vowel graphemes had only one possible phonemic correspondence. The Nonword Reading Task was administered after the Word Reading Task and on a separate day. RESULTS Each vowel categorization set (i.e., front, back) was analyzed separately. For each set, there were two different analyses. First, ANOVAs were carried out on the percentage of correct vowel classifications at Time 1 and Time 2. Percentage scores were retained because cell variances were not related to cell means, and, in all but one cell (CV items at Time 2), variances were very similar across cells. These analyses were carried out by subjects and items; only those effects that were significant in both the subject (F1) and item (F2) analyses were interpreted as statistically significant. For Set 1, where both CV and CVC items were included, the independent variables were vowel type, syllable type, and time. In Set 2, where only CVC-embedded vowels were evaluated, the independent variables were vowel type and time. In the second set of analyses, children’s miscategorizations on each vowel set were examined. Specifically, the analyses were carried out to determine if children’s errors were phonologically or phonetically motivated. Individual z tests of significantly different proportions were carried out to assess the distribution of errors for each vowel type at Time 1 and Time 2. Analyses were also carried out to examine the relationship between categorization ability and emergent literacy skills. These analyses involved comparing children’s relative performance on front versus back vowels for categorization, reading, and spelling tests. Vowel Categorization Tasks Stimulus Set 1: Front Vowels The mean percentages of correct classifications for /i/, /␧/, and /a/ were examined in a 3 (vowel type: /i/, /␧/, /a/) by 2 (syllable type: CV, CVC) by 2 (time: Time 1, Time 2) repeated measures ANOVA by subjects (see Table 1 for means); in the analysis by items, vowel type and syllable type were betweengroup factors and time was a repeated measure. Both analyses yielded main effects of syllable type, F1(1, 20) ⫽ 20.34, p ⬍ .001, F2(1, 30) ⫽ 21.72, p ⬍

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TABLE 1 Front Vowels: Mean Percentage Correct (and Standard Deviation) of Vowel Categorization as a Function of Time and Syllable Type Time Time 1

Time 2

Vowel

CV

CVC

CV

CVC

i ␧ a

69 (34) 64 (30) 65 (36)

56 (22) 46 (27) 51 (27)

96 (9) 96 (9) 96 (9)

88 (20) 85 (23) 85 (22)

.001, and of time, F1(1, 20) ⫽ 84.68, p ⬍ .001, F2(1, 30) ⫽ 256.64, p ⬍ .001. The syllable type effect was obtained because vowels in CV words were more accurately classified (M ⫽ 81%, SD ⫽ 28) than vowels in CVC words (M ⫽ 68%, SD ⫽ 29). The effect of time revealed the predicted pattern; children’s overall classification scores improved from Time 1 (M ⫽ 56%, SD ⫽ 30) to Time 2 (M ⫽ 89%, SD ⫽ 17). There were no other significant main effects or interactions. The absence of any significant results involving the factor of vowel type (Fs ⬍ 1) suggests that the three vowels in this group were classified with the same level of accuracy. The data were next analyzed for patterns of misclassification within each vowel category (see Table 2). If children’s miscategorization errors were not random, but rather reflected fuzzy boundaries between neighboring vowel phonemes, then the proportion of their miscategorizations to the closer vowel space neighbor should be significantly greater than chance. If in addition, the general vowel lowering tendency of Que´bec-French vowel phonology influences children’s vowel representations, then the vowel /␧/, which has two immediate neighbors, should be miscategorized to the lower neighbor /ɑ/ more frequently than to the higher neighbor /i/. Z tests of significantly different proportions were carried out on the frequencies of miscategorization for each vowel, syllable type, and testing period. For the vowel /i/, no systematic misclassification patterns emerged in CV words at either test time (z ⫽ 1.35 and z ⫽ 0.57, respectively, p ⬎ .05). That is, children were equally likely to misclassify /i/ words with /␧/ as with /ɑ/. In CVC words, misclassifications of /i/ words to /␧/ were significantly more frequent than misclassifications of /i/ words to /a/ at Time 1, z ⫽ 3.2, p ⬍ .01, but fell short of significance at Time 2, z ⫽ 1.78, p ⬎ .05. It is important to note that at Time 2, very few children made errors on this task. Thus although the general patterns of miscategorization obtained at Time 1 are also evident at Time 2, the small number of participants committing errors tended to preclude significant differences. When children made errors classifying /␧/ words at Time 1, they were significantly more likely to misclassify to /ɑ/ than to /i/ for CV items, z ⫽ 1.98,

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TABLE 2 Front Vowels: Frequency Distribution of Erroneous Categorizations by Vowel Type, Time, and Syllable Type (and Number of Participants Committing Errors) Time Time 1 Error type /i/ errors /i/ 3 /␧/ /i/ 3 /a/ /␧/ errors /␧/ 3 /i/ /␧/ 3 /a/ /a/ errors /a/ 3 /i/ /a/ 3 /␧/

Time 2

CV

CVC

CV

CVC

17 10 (n ⫽ 13)

52 24 (n ⫽ 21)

1 2 (n ⫽ 3)

14 6 (n ⫽ 7)

10 21 (n ⫽ 15)

35 58 (n ⫽ 20)

1 2 (n ⫽ 3)

12 14 (n ⫽ 8)

11 18 (n ⫽ 13)

25 60 (n ⫽ 21)

2 1 (n ⫽ 3)

3 23 (n ⫽ 9)

p ⬍ .05, and for CVC items, z ⫽ 2.39, p ⬍ .05. At Time 2, /␧/ to /i/ errors did not differ statistically from /␧/ words to /ɑ/ errors in either syllable type. The analysis of /ɑ/-word errors produced significant differences in CVC items but not in CV items. That is, in CVC words, children were significantly more likely to categorize /a/ words as /␧/ than as /i/ at Time 1, z ⫽ 3.80, p ⬍ .01, as well as at Time 2, z ⫽ 4.0, p ⬍ .01. The results for the front vowels demonstrated that at Time 1, before the children had any reading skills, most were able to categorize front vowels embedded in monosyllables above chance levels (⬎33%, t(20) ⫽ 6.24, p ⬍ .001), although their overall performance (M ⫽ 56%) suggested that the task was still fairly difficult. This result is consistent with previous findings with Englishspeaking children (Ehri et al., 1987). At retest, 6 months later, the children’s abilities improved dramatically, to 89%. As predicted, the main effect of syllable structure revealed that at both test times, the children found categorization easier when the vowel occurred in open than in closed syllables. Vowel type did not influence performance. The analysis of error patterns showed that children’s misclassifications were not, as a rule, random. In the following discussion, the focus is on the Time 1 data because at Time 2 the children made too few errors to obtain statistical significance, although the trends were in the right direction. When a nonlow vowel was misclassified it tended to be associated with its nearest lower neighbor; thus, /i/ was more likely to be classified as /␧/ than as /a/, and /␧/ was more likely to be classified as /a/ than as /i/. When the low vowel /a/ was misclassified, it was more

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TABLE 3 Back Vowels: Mean Percentage Correct (and Standard Deviation) of Vowel Categorizations as a Function of Vowel Type and Time Time Vowel

Time 1

Time 2

ɑ ɔ o

38 (27) 44 (22) 47 (19)

74 (31) 52 (23) 51 (26)

frequently associated with /␧/ than with /i/. The pattern of misclassifying vowels to their nearest neighbor was more prominent in CVC syllables, where four of the six comparisons were significant; in the case of the CVs, only the /␧/ 3 /i/ vs /␧/ 3 /a/ contrast at Time 1 reached significance. Nevertheless the distribution of children’s errors at Time 1 was similar for both CV and CVC syllables. Thus, the error distributions for /i/ words and /a/ words indicate that children’s vowel representations are influenced by the factor of articulatory similarity as evidenced by the greater number of confusions with nearer than with farther vowel space neighbors. However, the preponderance of /␧/ miscategorizations to /a/ at Time 1 was consistent with a general tendency in Que´bec French toward vowel lowering due to laxing and diphthongization. Stimulus Set 2: Back Vowels The percentages of correct categorizations for this vowel set at Time 1 and Time 2 are reported in Table 3. The main analyses in this condition did not include the factor of syllable type because two of the three vowels under examination do not occur in open monosyllabic words in French. As a result all of the items were CVCs. The data were submitted to a 2 (time: Time 1, Time 2) by 3 (vowel: /ɑ/, /ɔ/, /o/) ANOVA. Both factors were repeated measures in the analysis by subjects; in the item analysis, vowel type was a between-group factor and time was the repeated measure. In both analyses, the main effect of time was significant, F1(1,20) ⫽ 19.56, p ⬍ .001, F2(1,23) ⫽ 18.49, p ⬍ .001, as was the time by vowel type interaction, F1(2,40) ⫽ 7.70, p ⬍ .01, F2(2,23) ⫽ 6.92, p ⬍ .01. Post hoc tests (Newman–Keuls) revealed that the interaction was due to the children’s superior performance on /ɑ/ words at Time 2. That is, whereas the children’s classification accuracy for the three vowels was not significantly above chance at Time 1, their performance at Time 2 was significantly better on the vowel /ɑ/ relative to /ɔ/ and /o/. Moreover, whereas the children’s classifications of /ɑ/ words improved from Time 1 to Time 2, they did not improve significantly for /ɔ/ and /o/ words. The misclassification analyses for the errors in Set 2 (see Table 4) produced the following results. The vowel /ɑ/ was equally likely to be misclassified as /ɔ/ and

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TABLE 4 Back Vowels: Frequency Distribution of Erroneous Categorizations by Vowel Type and Time (and Number of Participants Committing Errors) Time Error type /ɑ/ errors /ɑ/ 3 /ɔ/ /ɑ/ 3 /o/ /ɔ/ /ɔ/ 3 /ɑ/ /ɔ/ 3 /o/ /o/ errors /o/ 3 /ɑ/ /o/ 3 /ɔ/

Time 1

Time 2

90 (28) 75 (28) (n ⫽ 21)

33 (38) 48 (38) (n ⫽ 17)

49 (31) 57 (31) (n ⫽ 21)

33 (28) 59 (28) (n ⫽ 20)

38 (23) 89 (23) (n ⫽ 22)

25 (24) 98 (24) (n ⫽ 19)

/o/, at both Time 1 and Time 2. At Time 1, the vowel /ɔ/ was as frequently misclassified with /ɑ/ as with /o/. At Time 2, however, the children were twice as likely to miscategorize /ɔ/ as /o/ than as /ɑ/, z ⫽ 2.7, p ⬍ .05. Finally, the children clearly demonstrated a misclassification bias in sorting words containing /o/. At both test times they were much more likely to categorize /o/ words as /ɔ/ than as /ɑ/; at Time 1, z ⫽ 4.57, p ⬍ .01; at Time 2, z ⫽ 5.34, p ⬍ .01. In sum, the children’s overall performance on this vowel set at Time 1 was at chance (t(20) ⫽ 1.96, p ⫽ .06) and there were differential developmental patterns for the vowel /ɑ/ versus /ɔ/ and /o/. Although the children found /ɑ/ as difficult to categorize as the other two vowels at the outset of the school year, they showed significant and specific improvement on this phoneme after 6 months of schooling whereas no significant improvement was observed for /ɔ/ and /o/. The error analyses further indicated that children treated each of these three vowels differently. Contrary to our predictions, children did not show a miscategorization bias for /ɑ/ words to the neighboring /ɔ/, nor of /ɔ/ words to the neighboring /ɑ/. On the other hand, they systematically detected a greater similarity between /o/ and /ɔ/ than between /o/ and /ɑ/. The implications of these finding are considered in the Discussion. Categorization of Front versus Back Vowels In a final set of analyses of the categorization data, we compared performance on front (Set 1) and back (Set 2) vowels at Time 1 and at Time 2. Because a subset of front vowel items was presented in the CV context, whereas all of the back vowel items were presented in the CVC context, potential superiority of

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TABLE 5 Mean Percentage Correct (and Standard Deviation) of Set 1 a (Front) and Set 2 (Back) Vowel Categorizations at Time 1 and Time 2 Time

a

Vowel set

Time 1

Time 2

Set 1 (front) Set 2 (back)

52 (18.71) 43 (17.73)

86 (17.56) 56 (17.73)

Set 1 results correspond to CVC items only.

performance on front vowels might be attributed to the easier CV items; therefore, only the scores from CVC front items were used in the following analyses. The overall percentage correct scores were submitted to a 2 (time: Time 1, Time 2) by 2 (vowel set: front, back) ANOVA by subjects, with both factors as repeated measures (see Table 5). In the item analysis vowel set was a between group factor and time was the repeated measure. Front vowels were categorized more accurately than the back vowels (F1(1, 20) ⫽ 40.40, p ⬍ .001; F2(1, 49) ⫽ 66.24, p ⬍ .001). Overall performance improved from Time 1 to Time 2 (F1(1, 20) ⫽ 39.79, p ⬍ .001; F2(1, 49) ⫽ 102.24, p ⬍ .001). There was also a significant interaction of time and vowel set (F1(1, 20) ⫽ 12.14, p ⬍ .01; F2(1, 49) ⫽ 20.50, p ⬍ .001). Post hoc analyses (Newman–Keuls) showed that, although front vowels were easier than back vowels (p ⬍ .05), there was greater improvement over time for front than for back items. Literacy Measures Spelling. In order to examine whether vowel spellings reflect a pattern of performance similar to that on vowel categorization, children’s relative ability to spell front (Set 1) versus back (Set 2) vowels was assessed. As in the previous analyses, only the CVC-item scores from Set 1 were included in these analyses. Separate t tests were conducted to examine relative performance on phonologically acceptable spellings and on conventional spellings. If vowel spelling ability depends to some extent on children’s ability to accurately represent vowel categories, then front-vowel spellings should be more accurate than back-vowel spellings. The analysis of phonologically acceptable spellings showed that front vowels (M ⫽ 85%, SD ⫽ 15.9) were not easier to produce than back vowels (M ⫽ 83%, SD ⫽ 12.8), t(20) ⫽ 0.57, p ⬎ .05. Thus, unlike the categorization results, these results indicated that children were as adept in spelling front and back vowels. However, an inspection of the spelling data for each vowel category revealed that the results for the /o/ words in particular may have been inflated by the confounding factor of orthography because /o/ can sometimes be represented by

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TABLE 6 Word and Nonword Reading: Mean Percentage (and Standard Deviation) of Vowels Read Correctly as a Function of Vowel Set and Word Type Vowel set Word type

Set 1 (front)

Set 2 (back)

Words Nonwords

92 (9.3) 86 (11.2)

73 (16.5) 49 (15.1)

o, which is the dominant vowel letter for /ɔ/. Thus, when children spelled /o/ in the words “saute” and “coˆne” with o (as the majority of children did), miscategorizations of /o/ as /ɔ/ could not be detected. In this sense, the analysis of conventional vowel spellings should provide a more stringent test of children’s vowel representations because conventional graphemes correspond more discretely to phonemes (e.g., au and oˆ correspond only to /o/). This analysis revealed that children produced significantly more accurate spellings for front (M ⫽ 69%, SD ⫽ 12.5) than for back vowels (M ⫽ 49%, SD ⫽ 14.0), t(20) ⫽ 6.44, p ⬍ .001. Thus, the conventional spelling data reflect the categorization data in that children had greater difficulty representing back vowels than front vowels. Children may have had more difficulty spelling back than front vowels because the vowel phonemes of front-vowel words were orthographically easier than the vowel phonemes of back-vowel words. To test this hypothesis, we calculated the number of invariant versus variant phoneme-to-grapheme vowel mappings across the words in each set. More specifically, ratios of the number of vowel phonemes with more than one possible corresponding grapheme versus phonemes with only one possible corresponding grapheme were calculated. Eight of the 18 front items contained vowels with variant vowel graphemes and 10 contained vowels with invariant graphemes. Four of the eight back items contained vowels with variant vowel graphemes and four contained vowels with invariant graphemes. These ratios were not significantly different from each other by a Fischer chi-square probability test (z ⫽ 0.55, p ⫽ .75). Thus, the spelling word sets were well equated in terms of orthographic complexity of the vowels. Reading. In the word and nonword reading analyses, a 2 (item type: word, nonword) by 2 (vowel set: front, back) repeated measures ANOVA was carried out on the percentage of accurately read vowels within words and nonwords. Only CVC items were included from the front vowel set (see Table 6). The analysis yielded main effects of item type (F(1, 20) ⫽ 68.92, p ⬍ .001) and of vowel set (F(1, 20) ⫽ 201.45, p ⬍ .001). These effects reflected children’s greater overall accuracy on words than on nonwords, and on the front vowels than on the back vowels. A significant interaction between these two factors was

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also obtained (F(1, 20) ⫽ 25.09, p ⬍ .001). Newman–Keuls tests revealed that although all four means were significantly different from each other (all ps ⬍ .05), nonwords with back vowels were most difficult to read. Perhaps, children performed better on front- than on back-vowel words because the vowel grapheme-to-phoneme correspondences were more invariant in the former set (thus allowing fewer alternative pronunciations). Conversely, perhaps children performed better on front nonwords than on back nonwords because there were more permissible pronunciations of the graphemes in back nonwords. Because the same vowel graphemes were used in both the word and the nonword tasks, one analysis is sufficient to address both concerns. Using a similar analysis to that described above for the spelling data, we computed the number of variant versus invariant grapheme–phoneme correspondences for each vowel grapheme, given its position and surrounding graphemes in the word (see Bruck et al., 1998, for a full description). The frequencies of invariant versus variant correspondences in each set of reading words were as follows: of the 20 front items, 2 contained variant vowel grapheme–phoneme mappings and 18 contained invariant mappings; all 11 back items contained invariant grapheme– phoneme mappings. There was no statistical difference by a Fischer chi-square probability test (z ⫽ ⫺1.11, p ⫽ .45) between these Set 1 and Set 2 words. The preponderance of invariant grapheme-to-phoneme mappings is to be expected given the nature of the French orthographic system, which is highly consistent in terms of grapheme–phoneme correspondences (although much less so in terms of phoneme-to-grapheme correspondences). The pattern of results on the spelling and reading tasks replicates the pattern found on the oral categorization tasks: Beginning readers of Que´bec French have greater difficulty in spelling and reading back vowels than front vowels. DISCUSSION The present study produced five main findings. First, Que´bec-French-speaking preliterate children, like their American-English-speaking peers, demonstrated poor command of categorical distinctions for front vowels adjacent on the height continuum. However, after 6 months of schooling Que´bec-French first graders achieved mastery of the task, which was accomplished by Ehri et al.’s (1987) American children only in second grade. Second, the ability to categorize vowels does not develop uniformly throughout the vowel space. Spectral proximity appeared to play a role in determining the development of children’s specific vowel representations. Third, children’s vowel categorizations are not independent of contextual (i.e., syllable structure) influences. Fourth, children’s categorization errors were not merely due to an inability to access the vowel phoneme (i.e., poor phonological awareness) but were frequently phonetically motivated and reflected fuzzy boundaries between vowel space neighbors. Finally, although schooling, and presumably direct instruction in grapheme–phoneme correspondences for vowels, influenced children’s explicit categorization performance,

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nonetheless, vowels that were difficult to categorize on oral tasks were also difficult to read and spell. Each of these findings is discussed in greater detail below. Crosslinguistic Comparisons of the Development of Vowel Categorization Que´bec-French children achieved very similar categorization accuracy scores on the front vowel set as English-speaking children participating in the study of Ehri et al. (1987). In that study, the accuracy score for beginning readers was 57%; the mean accuracy score in the present study was 56%. It would appear that at the outset of schooling, both language groups had developed similar levels of phonemic awareness for front vowels and both groups found the categorization of vowels along the height dimension quite difficult. However, the Que´bec-French children differed from their English counterparts in several respects. First, Que´bec-French children did not find any one front vowel more difficult than another. In contrast, English children found /␧/ words particularly difficult to categorize even in the second grade. Although the present data suggested a similar trend for /␧/ in the CVC context (which is also the context in which Ehri’s participants analyzed the sound) at Time 1, it was no longer evident 6 months later. Second, Que´bec-French first graders showed mastery of the task (M ⫽ 89%) after 6 months of schooling (mean age 6.6 years); their American peers did not reach this level of performance until the end of the second grade (mean age 8.3 years). Thus, development of front-vowel categories along the height dimension may be universally difficult for preliterate children, and categories located near the middle of the continuum may be especially difficult to establish. However, the present data suggest that the degree to which children’s explicit phonemic representations become crystallized or altered as a result of experience with alphabetic print is largely determined by aspects of the child’s oral and written input language. The Effect of Spectral/Articulatory Distances between Vowels on Categorization Development In order to determine if spectral (and articulatory) proximity of vowel space neighbors affects the development of vowel awareness, categorization of back vowels presented in CVC syllables was examined. In contrast with the frontvowel set, which differed on the single feature of tongue height, the back vowels differed in terms of two articulatory features, height and rounding (/ɑ/–/ɔ/) and height and laxing (/ɔ/–/o/); phonetically, however, these back vowels are realized in considerable proximity in the vowel space of Que´bec French. Categorization accuracy at Time 1 on back vowels was 43% and accuracy was similar for the three vowels. At Time 2, only /ɑ/ classifications improved significantly from the Time 1 levels. Finally, children performed better on front than on back items at both time periods; this difference was obtained even when the easier CV items were removed from the front-vowel data set. Thus children’s ability to explicitly

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represent spectrally close back vowels lagged well behind this same ability with front vowels which are spectrally further apart. These findings support the hypothesis that articulatory similarity (Ehri et al., 1987) and also spectral proximity negatively affect children’s representations of vowels. However, before accepting this conclusion, the role of two other potential factors which may have affected performance on the back-vowel set must be considered. First, it is possible that matching the stimuli to the target names was more difficult for the back than for the front vowels because the names of the target characters in the front set were embedded in open syllable words whereas, due to distributional constraints, the names of the target characters in the back set were embedded in closed syllable words. However, differences in the target names do not seem to be a likely confounding factor because during training, each vowel in the target names was extracted and produced in isolation several times by the experimenter in order to reinforce the differences between the names as well as to stress the critical vowel. Also, there was in fact less phonetic mismatch between the vowels in the stimuli of Set 2, where all stimuli were presented in the same syllable structure as the targets, than in the stimuli of Set 1, where the allophonic variation between the targets and the CV, CVC-short-, and CVC-long-vowel stimuli was considerably greater. A related difficulty was that the back-vowel target names ended in nasal consonants, which tend to mask some of the acoustic/articulatory information of preceding vowels. This masking may have rendered the target vowels more obscure. Although we cannot rule out this possibility, we again suggest that the presence of postvocalic nasal consonants was not the main cause of children’s difficulties with this vowel set because in Que´bec French the vowels /ɑ/, /ɔ/, and /o/ contrast with nasalized counterparts /ɑ˜ /, /ɔ˜ /, and /o˜/. Given these oral–nasal vowel contrasts in the children’s spoken language, the detrimental effect, if any, of postvocalic nasal consonants was presumably very small. A final concern pertains to possible differences between the relative frequency of occurrence of the front versus the back vowels in the spoken language. If back vowels are less frequent in spoken language than front vowels, children may find the latter vowels more difficult to categorize because they have less experience with them. Unfortunately, there are no data pertaining to phoneme frequencies in spoken Que´bec French and so this remains an open question. However, comparisons of the frequencies of occurrence in written language (Baudot, 1992) of the front- vs back-vowel categorization stimuli showed that the vowel stimuli were statistically indistinguishable from each other (t(61) ⫽ 0.36, p ⬎ .70). The Effect of Syllable Structure on Children’s Vowel Categorizations We asked whether 6-year-old children are able to represent and manipulate vowels independently of syllabic (i.e., consonantal) context. This issue is important because the phonemic representations of school beginners are influenced to

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some extent by surface phonetic characteristics of the surrounding sounds and hence are not impervious to phonetic variation (Ehri & Wilce, 1986; Ehri et al., 1987; Treiman, 1993; Treiman et al., 1995). It is of considerable theoretical interest to document when in development children consistently demonstrate the ability to map variant phonetic inputs to more abstract phonemic representations, and how the factor of alphabetic literacy might impact on this aspect of phonological knowledge. Only the data from the front-vowel set address this question. There was a significant effect of syllable structure. For all three vowels and at both test times, the children had greater difficulty categorizing CVC-embedded than CV-embedded vowels. A possible interpretation of this finding is that CVC items were more difficult to categorize not due to coarticulation effects on vowels in closed syllables, but rather because there was a greater similarity between the vowels in CV words and those presented in CV.CV target names than between the laxed and diphthongized variants in CVC words and their corresponding CV.CV targets. As discussed in the Introduction, if this factor were operating, then we should have obtained a vowel type by syllable type interaction such that the vowels / / and /␧/ should be less well categorized in CVC words than in CV words (because they undergo greater timbre changes in this context) whereas the vowel /a/ (which has a stable pronunciation across syllable types) should be equally well categorized in both syllable structures. This did not occur. Thus our results suggest that the vowel representations of school beginners are not independent of the coarticulated information of the ensuing consonant, and children continue to show this effect even after mastery of the categorization task and 6 months of literacy instruction. Fuzzy Category Boundaries as Reflected by Categorization Errors The finding that vowel categorization was more difficult for CVC items could simply reflect greater difficulty in accessing vowel segments in closed syllables because they are the medial segments in this context. Although this possibility has precedent in empirical studies of phonological awareness (e.g., Bruce, 1964; Kirtley, Bryant, MacLean, & Bradley, 1989), the miscategorization analyses further suggest that when task difficulty is increased by presenting closed syllable items, children are more likely to demonstrate poorly established category boundaries between vowel space neighbors. The extent to which children demonstrate fuzzy boundaries varies as a function of vowel type and (presumably) literacy experience. Specifically, the miscategorizations of front vowels were not random but rather reflected an effect of articulatory similarity as proposed by Ehri et al. (1987). As in Ehri’s study, children tended to miscategorize /i/ and /a/ with their immediate neighbor /␧/. However, the finding that at Time 1 children systematically misclassified /␧/ words with the lower neighbor /a/ suggests that an additional language-specific effect of vowel lowering in Que´bec French may also affect children’s category judgments. (These effects are more evident for CVC words than for CV words because a larger sample of data (errors) was obtained for the

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former class.) The claim that allophone-producing characteristics of the input language influence children’s vowel category formation would require further investigation, however, as no misclassification bias for /␧/ words was obtained at Time 2. The miscategorization patterns for the back-vowel set were less straightforward. Contrary to our prediction, children showed no bias at either test time to confuse /ɑ/ with /ɔ/, its immediate and very proximal vowel space neighbor. These data suggest that children perceive all three vowels to be members of one supercategory; this interpretation seems especially likely at Time 1, when children’s /ɑ/ categorization accuracy was essentially at chance (M ⫽ 38%). By Time 2, with /ɑ/ categorizations well above chance (M ⫽ 74%), many children recognized /ɑ/ as a separate category, but still appeared to treat /ɔ/ and /o/ as members of one category (i.e., when misclassifying /ɑ/, they did not detect a greater similarity with /ɔ/ than with /o/). In the case of /ɔ/ errors at Time 1, children were equally likely to misclassify it with /ɑ/ as with /o/, suggesting that they did not perceive /ɔ/ to be more like one or the other of the alternatives. This too is consistent with the idea that all three vowels were considered to be members of one supercategory at Time 1. (The explanation that task difficulty accounted for these null results does not seem likely because children’s performance on the same task was more accurate with front vowels.) At Time 2, however, the children were twice as likely to misclassify /ɔ/ as /o/ than as /ɑ/. Thus, after /ɑ/ begins to break off as an independent category, /ɔ/ and /o/ still seem to be considered as allophones of one category. Evidence indicating that children do detect a similarity between /ɑ/ and /ɔ/ was obtained from the spelling task given at Time 2. Although children’s spellings of /ɑ/ were phonologically accurate (M ⫽ 93%), their spellings of /ɔ/ were significantly less accurate (M ⫽ 69%). The most frequent phonological (and orthographic) misspelling of /ɔ/ was with a (17 of the 26 errors). Notably, whereas /ɔ/ and /o/ may share the same spelling of o, /ɔ/ never shares a spelling with /ɑ/; thus this misspelling bias is not influenced by orthographic factors but appears to be phonologically motivated. In the case of /o/ errors, the children demonstrated a strong bias to /ɔ/ at both test times, suggesting that /o/ is a better defined category than /ɔ/. This hypothesis is further supported by the vowel spelling data, where /o/ was most frequently represented with o and never with a. In summary, these data suggest that Que´bec-French children have ambiguous representations for back vowels and the ambiguity appears to reflect the proximity (articulatory/acoustic) between these vowel space neighbors. Relationships of Emergent Literacy Skills to the Development of Vowel Awareness Some of the data suggest that the acquisition of literacy skills influences the development of vowel awareness (although general maturation presumably also contributed to the children’s improved performance at Time 2). After 6 months of phonics instruction, Que´bec-French children’s categorization performance on front vowels was almost at ceiling. This level of mastery was achieved only in

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second grade by the English children in Ehri et al.’s study. The nature of the French orthographic system may account for the Que´bec-French children’s relatively rapid improvement. That is, vowel spellings are relatively more consistent in French than in English. Thus if learning grapheme–phoneme correspondences plays a disambiguating role in vowel phonology (see Ehri et al., 1987), the effect might become evident earlier in a more transparent writing system. Although differences in the method of instruction may have additionally contributed to the between-language differences, these were not likely to be major because both Ehri et al.’s group and the present Que´bec-French group were exposed to a phonics approach. The impact of literacy on the back vowel set appears to be limited to the vowel /ɑ/. Ironically, this categorization set may provide the stronger evidence for the disambiguating role of grapheme–phoneme knowledge on explicit vowel representations. That is, children may have shown the greatest improvement on /ɑ/-word categorizations because /ɑ/ never shares spellings with /ɔ/ and /o/, whereas these two vowels often share a common spelling o. Consequently, because the spelling input consistently distinguishes /ɑ/ from /ɔ/ and /o/, children may begin to appreciate the phonemic distinction despite the phonetic similarity especially between /ɑ/ and /ɔ/. For the distinction between /ɔ/ and /o/, however, neither the oral nor the written input signals a strong distinction between the two O’s, and as a result, the development of two distinct categories for this vowel pair may lag behind that for many of the other vowels. Other results suggest that the ability to accurately read and spell vowels depends on children’s categorization abilities. Analyses of the reading and spelling tests confirmed that, as in oral categorization, back vowels more difficult to read than front vowels. A similar pattern was obtained for the analyses of the conventional spelling data. In summary relative patterns of performance on front versus back vowels on each task are consistent and they support the view that phonemic representations and phonological skills are closely linked with emergent alphabetic literacy. Children do not have well-specified (adultlike) phonological representations for certain types of units and this is reflected on both reading and spelling tasks. Finally, the pattern of development, at least for front vowels, is very similar in preliterate speakers of English and French. Language-specific differences appeared to be due largely to differential effects of orthographic input. Clearly a full account of how children’s phonemic representations develop, and how their development relates to phonological awareness and to early literacy, will require much future research.

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APPENDIX A Key to Phonetic Symbols Used to Represent Phonemes in the Present Paper Front vowels Phoneme

Back vowels

QF variant

Example

Phoneme

ski pipe tire lait pe`re pe`re sac

/o/

/i/ [ ] [ i]/[e i] /␧/ [␧:] [a ␧] /ɑ/

QF variant

Example

[ou]

chaud rose

[ɑ ɔ]

botte dort

/ø/

/ɑ/ [ɑ ɔ]

paˆle faˆche

Note. QF ⫽ Que´bec French; // ⫽ phoneme; [] ⫽ phone.

APPENDIX B Vowel Categorization Task and Spelling a Items Set 1: Front Vowels

Set 2: Back Vowels

Practice items: rit, prix, quai, laine, rat, patte

Practice items: maˆle, pomme, paume

Test items:

CV

CVC

CVC (Long)

a

Test items: /i/

/␧/

/a/

lit nid a scie a ski pipe riche a dix rides a rive cire a tige a tire

paix a lait craie mets a bec a pelle a sel laide pe`re a neige reine verre a

bas a drap chat bras a sac a vache balle nappe a lave a rame a cage mare

⫽ Items included in the spelling test.

CVC

/ɑ/

/ɔ/

/o/

barre vase tasse chaˆle faˆche a paˆte part a phare tard

bol colle a robe a bottes corps port a fort dort a mord

doˆme coˆte coˆne a poˆle saute a mauve grosse jaune rose

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CARAVOLAS AND BRUCK Examples of phonologically acceptable and unacceptable vowel spellings Word

Phonologically acceptable

scie mets bas faˆche robe seau

Unacceptable

sci maine, me` ba fache robe so, sau, soˆ

sce me` baˆ, bo feou rabe soar

Reading Items Word reading items

Nonword reading items

Words from Set 1

Words from Set 2

Nonwords from Set 1

Nonwords from Set 2

nid rame rides paix pe`re bras riche verre lave pelle mare sac mets reine scie bas cire bec tige nappe

corps barre port faˆche fort saute part coˆne dort colle robe

mid pame lides zaix be`re pras siche berre chave relle dare rac dets teine zie jas mire tec rige dappe

vorps sarre chort raˆche gort laute nart boˆne vort tolle tobe

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