Memory for meaning and wording in concrete and abstract sentences

JOURNAL OF VERBAL LEARNING AND VERBAL BEHAVIOR

13, 682-697 (1974)

Memory for Meaning and Wording in Concrete and Abstract Sentences ~ SHANNON DAWN MOESER

Memorial University of Newfoundland Subjects were presented with sets of concrete and abstract sentences in a series of experiments. It was found that in nearly all cases subjects were better at identifying both meaning and wording changes in concrete sentences and subjects took significantly longer to encode and decode the abstract sentences. These results could not be explained in terms of either rated comprehension or lexical complexity. It was suggested that neither a dual-coding interpretation nor a semantic propositional coding model could adequately explain the results; thus an analogue semantic coding model was proposed.

Johnson, Bransford, Nyberg, and Cleary Begg and Paivio (1969) found that subjects presented with concrete sentences recognized (1972) challenged this interpretation. Using a changes in meaning (subject-object reversals) group of the Begg and Paivio sentences, they more easily than changes in wording (synonym found that subject-object reversal of concrete changes) while subjects presented with ab- sentences was considered by subjects to stract sentences detected changes in wording involve a greater change in meaning than more often than changes in meaning. They subject-object reversal of abstract sentences. explain these results in terms of Paivio's (1969) They also found that subjects asked to rate the dual-coding hypothesis: Concrete material concrete and abstract sentences on a compreis more likely to evoke imagery and thus be hension scale rated the abstract sentences as stored in a nonverbal semantic form; abstract more difficult to comprehend. Thus, they material has relatively limited access to argued, the Begg and Paivio sentences were not imagery and thus is more likely to be stored in equivalent either in comprehensibility of the acquisition sentences or in amount of change verbal associative form. The Begg and Paivio (1969) sets of concrete in meaning of the recognition test sentences, and abstract sentences were matched in terms and rather than reflecting different modes of word frequency rating, length of letters of storage, the Begg and Paivio results likely reflected differences in and syllables in words, and length of sentences more comprehension of the concrete and abstract in syllables. In a later study, Paivio and Begg (1971) found that there was a significant materials. Klee and Eysenck (1973) also questioned the difference in image arousal latencies to the Paivio and Begg (1971) finding that concrete two sets of sentences but no difference in and abstract sentences had equal comprecomprehension latencies. Thus they argued hension latencies. They defined comprehenthat the abstract sentences were as easy to understand as concrete sentences and differ- sion as the ability to make judgments on the ences in subjects' performance on the two meaningfulness of sentences and found that, types of sentences must be attributed to using this definition, significantly shorter comprehension latencies were produced in differences in mode of storage. response to concrete sentences and more errors This work was supported by National Research in judgment were made to abstract sentences. Council of Canada, Grant No. A-9638 to the author. Thus they agreed with Johnson et al. that I am indebted to Allan Paivio and Ted Rowe for the abstract sentences were more difficult to helpful comments on an earlier and shorter version of comprehend. this paper. Copyright © 1974 b y Academic Press, Inc. All rights o f reproduction i n a n y f o r m reserved. Printed in Oreat Britain

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EXPERIMENTI The measures of comprehension used by Paivio and Begg, Johnson et aI., and Klee and Eysenck were all measures of the comprehensibility of sentences that were perceptually available to the subjects, yet the basic question being investigated in their studies was whether concrete and abstract sentences are stored differently, Experiment I was designed to investigate whether there were differences in the difficulty of encoding the two types of sentences for a memory task. The study used a subset of the Begg and Paivio sentences which were rated by subjects to be equal in difficulty of understanding but different in ease of evoking imagery. Subjects were presented with the concrete and abstract sentences and asked to push a button when they had encoded the sentence, knowing that they would later be given a recognition test. Experiment I was also designed to test the Begg and Paivio results in light of the Johnson et aL criticism. Concrete and abstract acquisition sentences were equal in comprehensibility rating and the changes in recognition test sentences were by word substitution, not subject-object reversals.

Method Acquisition sentences. A subset of 25 abstract and 25 concrete sentences from the Begg and Paivio (1969) experiment was used. All were constructed using the same syntactical frame, in the form The (adjective) (noun) (verb) a (adjective) (noun). These sentences were part of a set of sentences from Rowe, Schurr, and Meisinger (1974) rated by a group of 55 paid volunteers from undergraduate psychology classes at Memorial University on a 7-point scale from "difficult to understand" to "easy to understand"; the final group of concrete and abstract sentences used were matched on this comprehensibility scale. The sentences were rated by another group of 15 Memorial University undergraduate student volunteers on a 7-point scale from "easy to imagine" to

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"difficult to imagine." The mean imaginability rating for concrete sentences was 6.20 and for abstract sentences 3.14. Test sentences. Two groups of test sentences were designed. One group consisted of sentences identical to the acquisition sentences and sentences which differed from the acquisition sentences by a change of one, two, or three words which did not change the meaning of the sentences. This group of test sentences was presented to the wording change condition and the concrete and abstract sentences were matched in terms of the mean number of synonyms substituted (2.25). The second group of test sentences consisted of sentences with synonym substitutions but identical meaning to the acquisition sentences and sentences with word substitutions which distorted the meaning of the acquisition sentences. These were presented to subjects in the meaning change condition. Each sentence which retained the original meaning was matched with its corresponding sentence which altered the original meaning in terms of the total number of words altered from the acquisition sentence. In addition, the concrete and abstract sentences were matched in terms of the mean number of words substituted (3.00). Examples of both types of test sentences are illustrated in Table 1. Three independent judges rated all the sentences as being changed or not changed in meaning by the substitutions and there was 100 ~ agreement among these judges. Apparatus. The sentences were presented on 35-ram slides projected by a Kodak 750 projector equipped with a Gerbrands shutter and control model Gl165, connected to a 5304 timer, a H/P 5055A digital recorder and a 5300A measuring system, and controlled by a hand-operated button switch. When the projector was switched on, the shutter opened and the timer began operating. When the button switch was pressed, the shutter closed, the timer stopped, and the printer printed out the time between the

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SHANNONDAWNMOESER TABLE 1 AN ILLUSTRATION OF THE CONCRETE AND ABSTRACT TEST SENTENCES

Concrete Acquisition sentence: The falling rock killed a

sinful captive. Test sentencesfor wording change condition:

The falling rock killed a sinful captive. The falling rock crushed a sinful captive. Test sentencesfor meaning change condition:

The plunging rock crushed a sinful prisoner. The plunging rock crushed a sinful guard. Abstract Acquisition sentence: The careful study resolved an

open question. Test sentencesfor wording change condition:

The careful study resolved an open question. The careful report resolved an open question. Test sentencesfor meaning change condition:

The careful report resolved an unanswered problem. The careless study left an unanswered question.

opening and closing of the shutter; then the projector advanced to the next slide and the shutter opened again. The time between the closing and opening of the shutter was 1.8 sec. The cycle repeated each time the button switch was pressed. Subjects. Twenty female undergraduate paid volunteers attending classes at Memorial University of Newfoundland were used. Ten were assigned to the wording change condition and 10 to the meaning change condition. Procedure. Subjects were tested individually. Each was shown how to operate the switch that changed the slides and was told that she could look at each slide as long as she wished. Subjects in the wording change condition were told that at the end of each group of 10 sentences they would be given a test. The test' would consist of 20 sentences, some of which were identical to the original sentences and some of which had the same meaning but with words changed. They would be required to state which were identical and which had changes in wording.

Subjects in the meaning change condition were given similar instructions, except that they were told that the 20 test sentences would consist of sentences with different wording from the originals but the same meaning, and sentences with different wording and meaning. They were required to state which had the same meaning ar/d which had a different meaning. Subjects were presented with a set of 10 acquisition sentences, five concrete and five abstract, in alternating order with a concrete sentence first. At the end of the 10 slides there was a blank, then the 20 test sentences randomly ordered. Subjects were required to say "same" or "different" to each test sentence, then press the switch to change to the next slide. At the end of the 20 test sentences there was another blank. Subjects were told how many errors they had made and asked if they had any further questions. Then they were presented with four similar sets of acquisition and test sentences, except that on the second and fourth trials an abstract sentence was the first presented. After each set of test sentences subjects were told how many sentences they had correct. The total session took about 50 rain per subject.

Results

The first set of acquisition and test sentences was treated as a practice trial; data were analyzed only on sets two through five. For each subject, mean encoding latencies on both concrete and abstract acquisition sentences were computed, mean decoding latencies on both concrete and abstract test sentences were computed, and mean correct answer scores for both concrete and abstract sentences were computed. (Sentences to which errors were made were not included in the computation of the mean decoding latencies.) These data are summarized in Table 2. Because of the wide disparities among subjects, medians are reported instead of means on the latency measures.

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TABLE 2 MEDIANLATENCIES(SEcs) ANDMEANNUMBEROF CORRECTANSWERSIN EXPERIMENTI Median encoding latency Condition Wording-changed Meaning-changed 2.

Concrete

9.06 9.70 9.38

Abstract

2.

10.79 9.93 13.66 11.68 12.23

Latencies. Because of the skewedness of the latency data, the analyses were performed on reciprocals of the latencies. For the encoding analysis, each sentence latency was entered individually (there was no summing across subjects or across sentences) and both subjects and sentences were treated as random effects as has been suggested by Clark (1973). The decoding analysis was similar except that the two versions of each sentence (for a given subject) were added together and entered as a single score. As it was difficult to compute the correct degrees of freedom with reciprocal data using the quasi-F formula, Clark's (1973) min F ' formula was used instead. On the encoding data, comparisons were made among the two conditions (meaning and wording changed), four sets of sentences, and two dimensions of sentence concreteness. The only significant effect found was between the concrete and abstract sentences, minF'(1, 50) = 16.51, p < .001. There were no other significant main effects and no significant interactions. Thus it t o o k significantly longer to encode abstract sentences than to encode concrete sentences, both when encoding was for meaning and when it was for wording, and there were no significant differences among sets in this respect. Similar comparisons were made on the decoding data. Significant main effects were found between the meaning and wording conditions, min F'(1, 2 3 ) = 46.50, p < .001, and between the concrete and abstract

Median decoding latency Concrete

Abstract

2

3.08 5.33 4.21

4.14 8.12 6.13

3.61 6.73

Mean number correct test sentences Concrete

Abstract

2.

9.33 9.05 9.19

8.55 7.85 8.20

8.94 8.45

sentences, minF'(1, 40) = 42.55, p < .001. There was no significant main effect due to sets, nor any significant interactions. Thus it t o o k longer to decode abstract sentences than concrete sentences in both group conditions and it t o o k longer to decode for meaning than to decode for wording with both types o f sentences. Correct answers. As the correct answer data was based on ls and 0s, the F ratios were computed respectively summing across subjects and summing across sentences, and then the m i n F ' formula used. A comparison of the two conditions, four sets, and two types of sentences showed only a significant main effect between the concrete and abstract sentences, minF'(1, 69)=10.70, p < . 0 0 5 . There were no other significant main effects and no significant interactions. Thus subjects were significantly better at recognizing both wording and meaning changes in concrete sentences than in abstract sentences. Although the results of the Begg and Paivio (1969) experiment suggest that there should have been a significant interaction between the type of change most easily identified and the concrete/abstract dimension, this was not found, minF'(1, 22) = .04. There was no significant difference between number of correct answers in the meaning change condition and in the wording change condition. Roughly 85 ~ of the sentences in the meaning change condition and 89 ~ of the sentences in the wording change condition were identified correctly.

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The test sentences varied in number of words changed, with an average of 2.25 synonyms being substituted in the wording change condition and 3.00 words being substituted in the meaning change condition. A linear trend analysis showed that in the wording change condition there was a significant linear trend ( p < . 0 1 ) ; the more synonyms that were substituted, the more likely the change was to be noticed. In the meaning change condition, however, there was no linear trend in either direction; in fact, slightly more meaning changes were noticed with three word substitutions than with either two or four. Lexieal complexity. Kintsch (1972) has found evidence that abstract nouns are often of a more complex lexical derivation than concrete nouns and that this factor, as well as the imagerY value of the word, affects paired-associate learning. The 40 sentences used in the data analysis were analyzed for lexical complexity. It was found that a slightly larger number of the abstract sentences contained more lexically complex nouns and also more complex verbs (Fodar, Garrett, & Bever, 1968). By chance, the major discrepancy in lexical complexity between concrete and abstract sentences was in the third set of sentences presented to subjects, the other sets being nearly equal in complexity of the two types of sentences. This suggests that lexical complexity was not a major factor in the results, because there were no significant differences due to sets on any of the measures. However, for a better test of this question, a subset of 12 concrete and 12 abstract sentences was chosen in which the different types of sentences were equal in lexical complexity (also controlled was the lexical complexityword frequency interaction). Each concrete sentence and its matched abstract sentence occurred in the same set. Analyses were run on these data comparing the two conditions and two types of sentences. On the encoding data there was a significant main effect between the concrete and abstract sentences,

minF'(l, 32) --- 5.87,p < .025; on the decoding data there were significant main effects due to group condition, minF'(1, 2 4 ) = 19.81, p < .001, and type of sentence, minF'(1, 3 5 ) = 21.47, p < .001; and on the correct answer data there was a significant main effect between the concrete and abstract sentences, minF'(1, 41) -- 10.68, p < .005. Thus, both when controlled for comprehensibility and when controlled for lexical complexity, it took longer to encode abstract sentences than concrete sentences, it took longer to decode abstract sentences than concrete sentences, and more errors were made in judging changes in abstract sentences than in concrete sentences. There were no significant interactions between the abstractconcrete dimension and the wording-meaning conditions on any measure and the only significant difference between the wording and meaning conditions was found in the decoding latencies. EXPERIMENTII In Experiment I there were significant differences between concrete and abstract sentences on all of the measures on which they were compared, and these differences could not be explained either by differences in comprehensibility of the sentences or by differences in lexical complexity of the sentences. Paivio's (1969) suggestion that abstract verbal materials are more likely to be forgotten was supported. However, the interaction between sentence concreteness and recognition of specific types of changes, which was reported by Begg and Paivio (1969), was not found. This may have been due to the fact that Begg and Paivio required their subjects to respond to both changes in wording and changes in meaning in the same experimental condition, whereas subjects in Experiment I were required to encode for either changes in meaning or changes in wording. It may be possible for subjects to manipulate their type of processing so that they are capable of responding to both types of change, although

MEMORY FOR MEANING AND WORDING

under normal circumstances they encode concrete material for meaning and abstract material for wording. Wanner (1968) found that when he instructed his subjects to attend to both changes in wording as well as changes in meaning, recognition for changes in meaning decreased, while recognition for changes in wording increased. Begg (1971) found that recognition memory for concrete sentences was much better for meaning than for wording and that the accuracy of meaning and wording judgments was uncorrelated. He concluded that memory for the meaning of concrete sentences was independent of the memory for their wording and that meaning was remembered as an image from which words were reconstructed. Thus it may be that if subjects are asked to encode sentences for both meaning and wording at the same time, they will tend to encode concrete sentences imaginally and thus lose the specific wording but they will encode abstract sentences verbally and thus show a better memory for wording changes in abstract sentences than in concrete sentences.

Method Materials and apparatus. The sentences and apparatus used in Experiment II were identical to those used in Experiment I with the exception that, of the test sentences used in the meaning condition of Experiment I, only those with the changed meaning were used. Design. As in Experiment I, 10 acquisition sentences were presented, followed by a recognition test, and five different sets of 10 sentences were used. The test now consisted of 30 sentences, 10 identical to the acquisition sentences, 10 changed in wording but not in meaning, and 10 changed in meaning. The test sentences were randomly ordered except that within each set of six there were two identical sentences (one concrete and one abstract), two wording changed sentences (one concrete and one abstract), and two meaning changed sentences (one concrete and one abstract).

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Subjects. Subjects were 10 undergraduate paid volunteers attending classes at Memorial University of Newfoundland. There were five males and five females. Procedure. The procedure was the same as the procedure followed in Experiment I except that subjects were now told that they would see three types of test sentences; sentences identical to the originals, sentences with wording changed but the same meaning as the originals, and sentences with both wording and meaning changed from the originals. They were required to state "identical," "wording changed" or "meaning changed" to each of the 30 test sentences. Results As in Experiment I, subject means on encoding latencies, decoding latencies, and correct answers were calculated on both concrete and abstract sentences for trials two to five. The median encoding and decoding latencies in Experiment II were very similar to those found in Experiment I: The median encoding latency of concrete sentences was 10.03 sec, of abstract sentences was 12.23 sec; the median decoding latency of concrete sentences was 5.42 sec, of abstract sentences was 7.47 sec. Analyses comparing the four trials by two types of sentences on the encoding data showed only a significant main effect due to concreteness, minF'(1, 21) = 8.04, p < .01. A similar analysis on the decoding data showed only a significant main effect due to concreteness, minF'(1, 38) = 17.66, p < .001. No other significant main effects nor any significant interactions were found on either set of data. These results were essentially the same as the results of Experiment I. Table 3 shows the mean number of each type of test sentence correctly identified by subjects. As in Experiment I, concrete sentences were more likely to be correctly identified than abstract sentences and this superiority was present both in the identification of wording changes and in the identification of meaning changes. The percentage of

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sentences correctly identified in Experiment II was 83 ~ . This appears to be slightly lower than the percentages found in Experiment I (85 ~ and 89 ~ ) but in Experiment I subjects had a 50 ~ chance of being correct, while in Experiment II they had only a one-third chance of being correct. If this chance factor

repeat Experiment II, this time allowing subjects only 5 sec to encode the sentences.

Method Materials. The sentences presented were identical to those used in Experiment II. Apparatus. The apparatus was the same as

TABLE 3 MEAN NUMBER OF SENTENCES CORRECTLY IDENTIFIEDIN EXPERIMENTSI I AND I I I

Identical Concrete Abstract ExFeriment II Experiment III

9.45 7.40

8.20 5.45

is taken into consideration, subjects were just as able to notice changes in Experiment II as they were in Experiment I. It appears to be no more difficult to remember both wording and meaning than it is to remember either wording or meaning. EXPERIMENT I I I

Neither Experiments I nor II found the interaction between concreteness of sentence and type of change identified which was reported by Begg and Paivio (1969). In both experiments subjects were significantly better at identifying both meaning and wording changes in concrete sentences, and both wording and meaning changes were identified equally well in the two types of sentences. Thus the question arises as to why these results differ from Begg and Paivio's. One reason may be that Begg and Paivio allowed their subjects only 5 sec to encode the sentences, while the average time taken by subjects in the present studies was more than double that. In Experiment I, subjects took exceptionally long to encode abstract sentences for meaning, so it may have been that subjects in the Begg and Paivio experiment did not have enough time to encode abstract sentences for meaning. Thus it was decided to

Wording-changed Concrete Abstract 8.60 6.70

7.60 5.60

Meaning-changed Concrete Abstract 8.45 7.10

7.35 4.55

that used in Experiments I and II except that the digital recorder and measuring system were not used. The projector was set to automatically change the slides at 5 sec or 10 sec intervals. Design. As in Experiment II, 10 acquisition sentences were presented, followed by 30 test sentences, and an experimental session consisted of five different sets of acquisition and test sentences. To control for the possibility that subjects might spend more time processing abstract sentences than concrete sentences, only the first (practice) trial consisted of both abstract and concrete sentences. For half the subjects, TriMs 2 and 4 consisted of abstract sentences, Trials 3 and 5 of concrete sentences. For the other half, this order of presentation was reversed. Subjects. Ten undergraduate paid volunteers attending classes at Memorial University of Newfoundland served as subjects. There were five males and five females. Procedure. The subjects were run in two groups of five. The instructions were the same as those given in Experiment II except that instead of being told that they could look at the sentences for as long as they wished they were told that the sentences would be presented automatically. Upon presentation of the test sentences they were asked to circle "Identical," "Wording Changed." or "Meaning Changed"

MEMORY FOR MEANING AND WORDING

on an answer sheet in front of them. The experimenter called out the number of the sentence as each test sentence was presented on the screen. Acquisition sentences were presented at 5 sec intervals, test sentences at 10 sec intervals. There was a 2 min break between trials. Results

The mean number of correct answers is shown in Table 3 and can be compared with the results of Experiment II. Concrete sentences were still more often correctly identified than abstract sentences and this was significant, minF'(1, 31) = 11.87, p < .005. There was a hint of an interaction; meaning changes in abstract sentences were identified much less frequently than wording changes, and wording changes in concrete sentences were identified slightly less frequently than meaning changes. This interaction was not, however, significant, minF'(2, 68) = 1.40,p > .10. EXPERIMENT I V

Thus far none of the experiments in this study have been able to duplicate the Begg and Paivio (1969) interaction. In Experiments I and II, wording changes in concrete sentences were as easily identified as meaning changes. In Experiment III it was found that with a reasonably fast presentation, wording changes in concrete sentences were less likely to be recognized than meaning changes, but the recognition of wording changes was much better than that recorded by Begg and Paivio. However, Begg and Paivio used only one synonym substitution per sentence, whereas in Experiment III there was an average of 2.25 synonym substitutions per sentence. It was found in Experiment I that the more words substituted, the more likely a wording change was to be noticed, but that this linear trend did not hold for meaning changes. Thus, if only one word were substituted in both conditions, it may make a more substantial difference between them. The recognition of

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wording changes should decrease while the recognition of meaning changes should be little affected. Another difference between this study and the Begg and Paivio experiment is that Begg and Paivio used subject-object reversals for meaning changes, whereas all the previous experiments in this study used word substitutions. Johnson et al. (1972) attributed part of Begg and Paivio's results to be due to the fact that their abstract sentences were less changed in meaning by subject-object reversals than their concrete sentences. However, it could be that subject-object reversals in in abstract sentences are more difficult to remember because of factors other than amount of meaning change. Begg (1972) has found that concrete phases are more redintegrative than abstract phrases; that is, the words that make up concrete phrases are more likely to be recalled together while the words that make up abstract phrases are more likely to be recalled as separate entities. This could be true of sentences as well, with abstract sentences less likely to be recalled as holistic entities than concrete sentences. Thus abstract sentences that involve no new words, just different configurations of previously presented words, might be more difficult to recognize as new. Finally, Begg and Paivio used a different response measure than has been used in this series of studies. Their subjects only had to state whether a sentence was changed or not changed from the original sentence. The subjects in this series of experiments had to identify whether the change was a meaning change or a wording change, and conceivably these differences in measuring techniques might interact with the concrete-abstract dimension. In Experiments II and III this possibility could not be investigated because subjects were exposed to both types of changes. However, by exposing subjects to only one type of change, but still having them delineate whether it was a meaning or wording change, this question can be investigated.

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Therefore, it is argued that the Begg and Paivio interaction effect may have been a result of the specific type of test sentence and specific response measure used by Begg and Paivio. Experiment IV was designed to test how subjects encoding the same sentences reacted to different types of test sentences and whether there was a difference due to type of response measure used. A new set of sentences was used because most of the sentences in the previous experiment were not reversible. The concrete and abstract test sentences were matched so that the subjectobject reversals were equally different in meaning from the acquisition sentences, the word substitutions for meaning changes were equally different from the words used in the acquisition sentences, and the synonym substitutions for wording changes were equally similar to the words used in the acquisition sentences.

Method Test sentences. A number of concrete and abstract sentences were constructed in which the subject and object could be meaningfully reversed and this reversal changed the meaning of the sentence. All these sentences used the syntactical frame The (adjective) (noun) (verb) a (adjective) (noun). The noun pairs and adjective pairs from each sentence were presented to 35 undergraduate students who were asked to rate each pair on a fivepoint scale from very different in meaning to very similar in meaning. A final group of 10 concrete and 10 abstract sentences was chosen on the basis of this rating, such that both types of sentences had equal overall noun and adjective difference ratings. The two types of sentences were also matched as closely as possible on word frequency. (The abstract sentences had a slightly higher overall word frequency rating.) Then each of the 20 sentences was paired with its subjectobject reversal and these new pairs were rated by a new group of 20 paid undergraduate volunteers on a 7-point scale from very

different in meaning (1) to very similar in meaning (7). No significant differences were found between the ratings on the two types of sentences. The concrete pairs had a mean rating of 1.56; the abstract pairs a mean rating of 1.46. Words were substituted for the subjects of these sentences which changed the sentences' meanings. Again word pairs were formed, this time between the word substitutions and the subjects they were substituted for, and each pair was rated by a group of 33 undergraduate paid volunteers on a 5-point scale from very different to very similar in meaning. The concrete and abstract sentences were matched as closely as possible on this rating. The concrete sentences had a mean score of 2.53; the abstract sentences, 2.35. Finally, synonyms were substituted for the subjects of each sentence and a similar rating obtained on these word pairs by 20 paid undergraduate volunteers. The mean difference rating for the concrete sentences was 4.40; for the abstract sentences, 4.58. Thus there was a base set of 20 acquisition sentences and three different types of test sentences for each acquisition sentence, a subject-object reversal which changed the meaning of the acquisition sentence, a word substitution which changed the meaning of the acquisition sentence, and a synonym substitution which did not change the meaning of the acquisition sentence. The concrete and abstract sentences were matched as nearly as possible on all these variables. Apparatus. The apparatus used in Experiment IV was identical to that used in Experiment III. Design. Six experimental conditions were used, with subjects receiving either concrete or abstract sentences (but not both) and only one of the three types of sentence changes. Ten acquisition sentences were presented followed by 20 test sentences. The test sentences consisted of the 10 changed sentences (the type of change depending on the experimental group the subject was in) and 10 sentences identical to the aquisition sen-

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tences. The test sentences were in random order but all groups had the same order for acquisition and test sentences. Even the concrete and abstract sets were matched in this way; for instance, the first test sentence would be identical to the second acquisition sentence; the second test sentence would be the test change of the first acquisition sentence; and SO o n .

Subjects. Sixty undergraduate paid volunteers attending classes at Memorial University of Newfoundland served as subjects. There were five males and five females in each group. Procedure. The subjects were run in groups of two to four. All subjects were given identical instructions, namely, that they would be shown some sentences, then they would be tested on how accurately they could remember these sentences and that the test sentences could involve changes in meaning or changes in wording that did not affect the meaning of the sentence. The acquisition sentences were presented at the rate of one sentence every 5 sec; the test sentences at the rate of one every 10 sec. U p o n presentation of the test sentences subjects were asked to circle "Identical," "Wording Changed" or "Meaning Changed" on an answer sheet in front of them.

changed, or wording changed as was done in the two previous experiments. However, this experiment differed from these previous experiments in that subjects were exposed to only one type of change. Thus a changed score could also be taken; that is, a score which ignored the distinction between meaningchanged and wording-changed responses and scored only "identical" or "changed" responses. The changed score would never be lower than the exact score, because a subject must know that a change occurred before he could identify the type of change that occurred. I f the difference between the changed and exact score is the same for all groups, it suggests that only random guessing errors have been made. If, however, this difference shows significant effects among groups, it may tell us something about how subjects are processing these sentences. The mean number of correct sentences identified for each of the six groups is shown in Table 4. As can be seen, with concrete sentences, the synonym substitution group had the lowest score and the subject-object reversal groups had the highest score, in both the exact measure and the changed measure. With abstract sentences, the subjectobject reversal group had the lowest score and

TABLE 4 MEAN NUMBER OF CORRECT SENTENCES IN EXPERIMENT I V

Using exact measure

Using changed measure

Condition

Concrete

Abstract

Concrete

Abstract

Subject-object reversal Word substitution Synonym substitution X

14.7 13.4 9.9 12.7

8.0 8.3 11.2 9.2

16.8 16.5 10.9 14.7

11.1 13.5 13.7 12.8

Results The results of Experiment IV could be scored in two different ways. First, a sentence could be scored as correct only if it were correctly identified as identical, meaning

the synonym substitution group had the highest score, in both the exact measure and the changed measure. An analysis comparing the six groups on the exact score showed a significant main

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effect between the concrete and abstract sentences, minF'(1, 2 9 ) = 9.00, p < .01, and a significant interaction between sentence concreteness and type of change, minF'(2, 85) = 10.03, p < .001. As in all the previous experiments, subjects were still better at identifying specific changes in concrete sentences than in abstract sentences, but for the first time there was a significant interaction between sentence concreteness and type of change. When the six groups were compared using the changed score, there were no significant main effects, but a significant interaction between sentence concreteness and type of change was found, minF'(2, 81)=10.59, p < .001. Using the changed measure eliminated the significant differences between concrete and abstract sentences but did not affect the significant interaction. This was the same result that Begg and Paivio (1969) reported. These results show that it was particularly difficult for subjects to notice changes in abstract sentences which involved subjectobject reversals. As the concrete and abstract sentences used in this experiment were rated as equally changed in meaning by the subjectobject reversals, it must be that this difficulty has some connection with how the subjects process abstract sentences in memory. Also, the only time in this set of experiments that no significant difference has been found between the concrete and abstract sentences was when the changed response measure was used. The major reason for this "no significant difference" was the poor identification of changes by subjects in the concrete wording change group. The data could also be analyzed using a contrived score obtained by taking the difference between the exact and changed response measures. An analysis of the six groups on this score showed a significant main effect due to sentence concreteness, minF'(1, 36)=4.22, p < 0 5 and type of sentence change, minF'(2, 89) = 3.31, p < .05.

The interaction was not significant. Thus there was a significantly smaller difference between the exact score arm the changed score with concrete sentences, and for both concrete and abstract sentences the difference between the exact and changed score was greater in the meaning-change conditions than in the wording-change conditions. The larger discrepancy between exact and changed measures on abstract sentences coupled with the lower overall score on abstract sentences suggests that there is a greater chance factor involved in the identification of abstract sentences. The larger discrepancy between exact and changed measures in the meaning-change conditions, however, does not suggest that there is a greater chance factor involved in the identification of meaning changes; the meaning-change groups were superior to the wording-change groups on overall score. Rather it suggests that subjects had a bias towards identifying changes as wording changes if they were not certain of the type of change that had taken place. This ties in with the results of Experiment I where it was found that wording changes were decoded significantly faster than meaning changes. It appears that the identification of a change in a sentence's wording occurs prior to the identification of whether that change in wording affects the sentence's meaning. This explains why in Experiments III and IV, synonym substitutions in abstract sentences were identified more accurately than word substitutions (meaning changes). Subjects noticed the change, but were biased toward identifying it as a wording change rather than a meaning change. This also suggests that at least a partial answer as to why subjects were so poor at identifying synonym substitutions in concrete sentences in Experiment IV and in the Begg and Paivio experiment may lie with these response biases. The response bias could change if subjects are able to eliminate the possibility of a meaning change having occurred, and

MEMORY FOR MEANING AND WORDING

this is much more likely to occur with concrete sentences than with abstract sentences. EXPERIMENT "V

Only in Experiment IV and in the Begg and Paivio experiments were synonym substitutions in concrete sentences identified less frequently than synonym substitutions in abstract sentences. It was suggested that this may have occurred because of response biases rather than because of differences in the encoding process. If this is so, different decoding instructions should affect the results but different encoding instructions should not. Therefore subjects told to decode for wording only should show similar results no matter what the encoding instructions; however, subjects told to decode for both wording and meaning should show different results than those told to decode for wording, even if their encoding instructions are the same. Also, the sentences used in Experiment IV were never manipulated with regards to their encoding time. With the other set of sentences, the recognition of wording changes in concrete and abstract sentences was equally affected by the faster encoding requirement. (The semblance of an interaction occurred in Experiment III because of the differential effect of the faster encoding period on meaning changes; there was no tendency towards a differential effect of encoding time on wording changes.) However, these test sentences had an average of more than two synonym substitutions per sentence. This made the identification process much easier. In the more difficult identification task, changes in the processing time may have a differential effect on the sentence types.

Method Test sentences. The same test sentences in the same random order were used in Experiment V as were used for the synonym substitution groups in Experiment IV. Design. Experiment V consisted of two

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small separate experiments. Experiment Va investigated whether differences in encoding or decoding instructions would affect the identification of synonym substitutions. Three instruction conditions were used. One set of subjects were told to encode for meaning and wording and decode for meaning and wording (as in Experiment IV). The second set were told to encode for meaning and wording and decode for wording. The third set was told to encode for wording and decode for wording. Experiment Vb allowed subjects to encode and decode the sentences at their individual rates as was done in Experiments I and II. Apparatus. For Experiment Va, the apparatus was identical to that used in Experiments III and IV; for Experiment Vb, the apparatus was identical to that used in Experiments I and II. Subjects. Eighty paid volunteers attending classes at Memorial University of Newfoundland served as subje~s. Ten subjects (five males and five females) were assigned to each experimental condition. Procedure. The procedure for Experiment Va was as follows. Subjects were run in groups of one to five at a time. Those subjects given the meaning and wording encoding instructions were told that they would see ten sentences and then they would be tested on their recognition of meaning and wording changes in these sentences. They were shown the ten aeqnisition sentences. Those with meaning and wording decoding instructions were given the same answer sheet as used in Experi,ment IV and asked to identify the test sentences as "Identical", "Meaning Changed" or "Wording Changed." Those subjects with wording decoding instructions were told that their test would consist of wording changes only and were given an answer sheet which asked them only to identify the test sentences as "Identical" or "Changed." Subjects given both encoding and decoding instructions for wording were told at the onset of the experiment that their recognition task would consist

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only of changes in wording. Subjects were assigned to one of the three instruction conditions and were shown either concrete or abstract sentences; thus there were six experimental conditions in Experiment Va. The 10 acquisition sentences were presented at the rate of one sentence every 5 sec; there was a 2 min break, then the 20 test sentences were shown at the rate of one sentence every 10 sec. For Experiment Vb subjects were run individually. They were told that they would be tested on their recognition of wording changes and that they could look at each sentence for as long as they wished. They were required to state whether each test sentence

on concrete sentences in Experiment Vb. An analysis of Experiment Va, comparing the three types of encoding instructions and two dimensions of sentence concreteness showed no significant main effects or interaction. Although the direction of the means supports the response bias hypothesis, this support was not significant. However, there was also no support for the Begg and Paivio finding that wording changes in abstract sentences were more likely to be noticed than wording changes in concrete sentences. An analysis of Experiment Vb found a significant difference between the concrete and abstract sentences, minF'(1, 3 5 ) = 6.77, p < .025. Thus when subjects were given

TABLE 5 MEAN NUMBER OF CORRECTLY IDENTIFIEDSENTENCESIN EXPERIMENTV

Five-second encoding Sentences

Group 1"

Concrete Abstract )~

11.8 13.0 12.4

Group 2b Group 3c 12.7 13.3 13.0

13.8 12.8 13.3

Unlimited encodinga 16.5 13.5 15.0

" Meaning and wording encoding and decoding instructions. b Meaning and wording encoding, wording decoding instructions. c Wording encoding and decoding instructions. a Experiment Vb. was identical or changed from the acquisition sentence.

Results The mean number of correctly identified sentences for each of the eight experimental conditions is shown in Table 5. (Meaningchanged and wording-changed responses were added together to get the total changed score for G r o u p 1.) There appeared to be little difference i n the mean scores obtained in all these conditions except for a slightly lower score on concrete sentences for G r o u p 1 (meaning and wording instructions in both encoding and decoding) and a higher score

as much time as they wished to encode the sentences, they were superior at identifying synonym substitutions in concrete sentences. The latency data was also analyzed. The median time taken for encoding the concrete sentences was 13.96 see; the abstract sentences, 14.36 see. The median decoding time on concrete sentences was 7.68 sec; on abstract sentences, 7.78 sec. Neither of these differences were significant. This result differs from those found in Experiment I but it can probably be explained by the variability among subjects (a between-subjects design was used in Experiment Vb while a within-subjects design was used in Experiment I) and the fact that sub-

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jects were not given a practice session in order to familiarize themselves with the experimental procedure. GENERAL DISCUSSION

The results of this set of experiments suggest that the interaction between sentence concreteness and identification of meaning or wording changes that was reported by Begg and Paivio (1969) was due more to the particular experimental design used by Begg and Paivio than to the differences in comprehensibility of the concrete and abstract sentences found by Johnson et aI. (1972) and Klee and Eysenck (1973). If differences in comprehensibility was the major factor in the Begg and Paivio results, few, if any, differences should have been found in Experiments I, II, and III when concrete and abstract sentences were matched in comprehensibility. However, in all three experiments the concrete sentences were significantly more accurately recalled, and in Experiments I and II the concrete sentences were encoded significantly faster and decoded significantly faster. When comparisons were made on a subset of these sentences matched for lexical complexity, the same results were obtained. Thus the superiority of concrete sentences in memory tasks is not only a function of comprehensibility or lexical complexity. The imagability of a sentence has a strong effect on how easy it is to store and retrieve that sentence. The effect of sentence concreteness on memory processing was found not only when subjects were required to encode for meaning but also when they were specifically instructed to encode for wording. It appears that concrete sentences have easier access to verbal information as well as semantic information, even when matched on such verbal indices as word frequency, comprehensibility, and lexical complexity. Both Bregman and Strasberg (1968) and Rowe, Schurr, and Meisinger (1974) have suggested that syntactic information may be incorpor26*

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ated into the semantic representation rather than by the use of explicit coding elements. The results of these experiments suggest that information relevant to the retrieval of specific wording may also be incorporated into the semantic representation. This accords with Anderson and Bower's (1973) proposal that linguistic information is attached "parasitically" to the perceptually based memory system, and that the basic organization of the memory component is semantic. In contrast, Paivio (1969; 1971) has proposed that we have two memory systems, a semantic (imaginal) coding system and a verbal (linguistic) coding system. Begg (Begg & Paivio, 1969; Begg, 1971) contends that concrete sentences have less access to the verbal code because they are more likely to be stored as nonverbal images. No support for Begg's argument was found in the present experiments; in fact the results of Experiments IV and V suggest that the Begg and Paivio results which support this argument can be better explained in terms of subjects' response biases than in terms of memory coding processes. Dual-coding theory does not explain the memory superiority for specific wording of concrete sentences found in Experiments I, II, III, and Vb and the significantly longer encoding and decoding latencies on abstract sentences in Experiment I when subjects knew that they were to encode only for wording. If coding for meaning and coding for wording are independent processes, why should a longer processing time be of more assistance in recognizing synonym changes in concrete sentences than in abstract sentences (as in Experiment Vb)? Why should it take longer to encode and decode verbal information from abstract sentences (as in Experiment I), unless the subject can utilize verbal information only in conjunction with semantic information, in other words, unless the verbal information is processed via a semantic code ? Thus it appears that the best explanation of these data can be offered by a semantic

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coding model, but the model must be able to account for the differences found between concrete and abstract sentences. Of the several semantic coding models which have been proposed (for example, Clarke & Chase, 1972; Trasbasso, 1972; Anderson & Bower, 1973) all have used a prepositional approach which cannot explain differences in the storage and retrieval of sentences which differ only on an imaginability measure. A better explanation, I believe, can be offered by an analog semantic coding model which proposes that memory representation is organized in terms of iconic groupings, functionally unitary, integrated memory structures. They are described as iconic in the sense that they utilize principles similar to, although not necessarily analogous with, the imaginal representation of the sentence; it is assumed that sentences that are easier to represent in imagery are also easier to translate into this memory code. The analog semantic coding model also can explain an important question which has, up to now, been ignored in the discussions; why sentences which were so different in comprehensibility when measured by encoding latencies were rated by subjects as being equal in comprehensibility. The comprehensibility of these sentences varied depending on how it was measured. When a latency measure was used, and subjects simply asked to indicate when they understood a sentence, no significant differences were found between the concrete and abstract sentences (Paivio and Begg, 1971). When subjects were asked to rate the sentences on a comprehension scale, there were significant differences between the concrete and abstract sentences (Johnson et al., 1972). When, in the present experiment, the two types of sentences were equated on comprehension rating, there were still significant differences between the concrete and abstract sentences in encoding and decoding latencies and in number of sentences correctly remembered. All these results were obtained on the same set of sentences.

The explanation for this variance may lie in how subjects approach the definition of comprehension. Under certain circumstances they may simply judge the difficulty of representing the individual words, rather than dealing with how difficult it is to form the complete sentence into one integrated representation. Given a memory task, however, the integration operation assumes greater importance, as it becomes necessary to remember which word or phrase is associated with which other words or phrases. Defining comprehension as the integration of ideas or formation of a holistic representation is very similar to the way in which Brantford and his associates (for example, Bransford & Franks, 1971; Bransford, Barclay, & Franks, 1972; Bransford & Johnson, 1973) use the term. However, by explicitly tying the definition to an analogue model of memory, differences between the comprehension measures can be explained. It is suggested that, to subjects, comprehension can refer either to representations of individual words or to a representation of the holistic idea. In the present experiment, the individual words were equally understandable in the sense that they had equal access to some form of representation, but the abstract words and sentences were more likely to be represented in a partial form because their complete representation involved mo~e complex integrative operations. The concrete words and sentences were more likely to be encoded in an integrated form.

REFERENCES ANDERSON,J. R., & BOWER, G. H. Human associative memory. Washington, D.C. : Winston, 1973. ATWOOD, G. An experimental study of visual imagination and memory. Cognitive Psychology, 1971, 2, 290-299. BEGG, I. Recognition memory for sentence meaning and wording. Journal of Verbal Learning and VerbalBehavior, 1971, 10, 176-181. BEGG, I. Recall of meaningful phrases. Journal of Verbal Learning and Verbal Behavior, 1972, 11, 431-439.

MEMORY FOR MEANING AND WORDING BEG6, I., & PAIVlO, A. Concreteness and imagery in sentence meaning. Journal of Verbal Learning and Verbal Behavior, 1969, 8, 821-827. BOWER, G. H. Imagery as a relational organizer in associative learning. Journal of Verbal Learning and Verbal Behavior, 1970, 9, 529 533. BRANSFORD, J. D., BARCLAY, J. R., & FRANKS, J. J. Sentence memory: A constructive versus interpretive approach. Cognitive Psychology, 1972, 3, 193-209. BRANSFORD, J. D., & FRANKS, J. The abstraction of linguistic ideas. Cognitive Psychology, 1971, 2, 331-350. BRANSFORD, J. D., & JOHNSON,M. K. Consideration of some problems of comprehension. In W. G. Chase (Ed.), Visual information processing, New York: Academic Press, 1973. BREGMAN,A. S., & STRASBERG,R. Memory for the syntactic form of sentences. Journal of Verbal Learning and Verbal Behavior, 1968, 7, 396-403. CLARK, H. H. The language-as-fixed-effect fallacy: A critique of language statistics in psychological research. Journal of Verbal Learning and Verbal Behavior, 1973, 12, 335-359. CLARK, H. H., & CHASE, W. G. On the process of comparing sentences against pictures. Cognitive Psychology, 1972, 3, 472-517. FODOR, J. A., GARRETT, M., &BEVER, T. G. Some syntactic determinants of sential complexity. II: Verb structure. Perception & Psychophysies, 1968, 3, 453-461. FRANKS, J. J., & BRANSEORD, J. D. The acquisition of abstract ideas. Journal of Verbal Learning and Verbal Behavior, 1972, 11, 311-315. JOHNSON, M. K,, BRANSFORD, J. D., NYBERG, S. E., & CLEARY, J. J. Comprehension factors in inter-

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preting memory for abstract and concrete sentences, Journal of Verbal Learning and Verbal Behavior, 1972, 11, 451-454. KINTSCH, W. Abstract nouns: Imagery versus lexical complexity. Journal of Verbal Learning and Verbal Behavior, 1972, 11, 59-65. KLEE, H., & EYSENCK, M. W. Comprehension of abstract and concrete sentences. Journal of Verbal Learning and Verbal Behavior, 1973, 12, 522-529. PAIVlO, A. Mental imagery in associative learning and memory. Psychological Review, 1969, 76, 3, 241-263. PaIvlo, A. Imagery and verbal processes. New York: Holt, Rinehart & Winston, 1971. PAIVIO, A., & BEGG, I. Imagery and comprehension latencies as a function of sentence concreteness and structure. Perception & Psyehophysics, 1971, 10, 408-412. REESE, H. W. Imagery and contextual meaning. Psychological Bulletin, 1970, 73, 404414. ROWE, E. J., SCHURR, B., & MEISlNGER, D. Cued recall of concrete and abstract sentences. Unpublished paper, 1974. TRABASSO, T. Mental operations in language comprehension. In R. O. Freedle & J. B. Carroll (Eds.), Language eomprehension and the acquisition of knowledge. Washington, D.C. : Winston, 1972. WANNER, U. E. On remembering, forgetting, and understanding sentences: a study of the deep structure hypothesis. Unpublished doctoral dissertation, Harvard University, Cambridge, Massachusetts, 1968. (Received June 24, 1974)