Hierarchical semantic organization in educable mentally retarded children

JOURNAL

OF EXPERIMENTAL

Hierarchical

CHILD

PSYCHOLOGY

27,277-285

(1979)

Semantic Organization in Educable Mentally Retarded Children

NILA

N. BENDER University

of

AND N. S. JOHNSON Cafifornia,

Riverside

Fifty-four educable mentally retarded (EMR) children looked at eight familiar pictures. Subsequently they attempted to recall each picture when given as retrieval cues the corresponding noun and four other words that represented a hierarchical class inclusion system for that particular picture. Five predictions based on a model of semantic distance in the structure were tested. Four of the predictions were significantly confirmed. Thus, EMR children showed evidence of functional use of a hierarchical class inclusion system in memory retrieval. These results are not suggested by most of the relevant literature in mental retardation.

Several studies have offered evidence that semantic organization in the memory of adults can be represented at least in part by a class inclusion hierarchical structure (cf. Anderson, 1972; Collins & Quillian, 1969). Quillian’s (1968, 1969) model has best explained hierarchical semantic organization. He has suggested that meaning can be viewed as interconnecting nodes in a semantic network. Each node represents a concept that is superordinate to all below it, and each concept at a lower level on the tree is included within each of the superordinates on the path leading upward from it. Most studies of young normal children have not shown that they organize information in such tree-like structures (cf. Anglin, 1970; Inhelder & Piaget, 1964). However, Steinberg and Anderson (1975) found that six-year-old children of normal intelligence can use a class inclusion hierarchy. Studies of mentally retarded children’s hierarchical semantic organization typically measure clustering in free recall. Jensen (1970) maintained that mentally retarded children lack organizational or conceptual skills Copies of the paper may be obtained from the first author at the School of Education, University of California, Riverside, CA 92521. The authors wish to thank the administrators, teachers, and children of the following schools for their kind cooperation: Alvord Unified School District, Colton Joint Unified School District, Gateway Nursery School, and Riverside Unified School District. The study was supported in part by U. S. Office of Education Grant OEG GOO-74-02852. 277 0022-0%5/79/020277-09$02.00/O Copyright @ 1979 by Academic Press, Inc. Ail rights of reproduction in any form reserved.

218

BENDER

AND JOHNSON

involved in using a class inclusion hierarchical system, and indeed several studies have shown that the mentally retarded do not cluster as much as non-retarded (cf. Gerjuoy & Spitz, 1966; Rossi, 1963; Stedman, 1963). However, Palmer (1974) and Riegel and Taylor (1974) found no significant differences in clustering between retarded and nonretarded groups, though both showed a nonsignificant trend favoring the normal children. Spitz (1966) has suggested that the mentally retarded person does not spontaneously organize material as well as he stores it, and retrieval reflects this lack of organization. However, if organization is imposed, the mentally retarded person does make use of it: Retrieval is better organized and more accurate (Bilsky, Evans, & Gilber, 1972; Gerjuoy & Spitz, 1966; MacMillan, 1972). While free recall designs give information about grouping or categorizing members of a superordinate term, the Steinberg and Anderson paradigm reveals information about the use of a class inclusion system in retrieval. In their task the subject is verbally given five cue words for each conceptual hierarchy. For each retrieval cue, the subject is asked which picture that he had seen previously reminds him of the cue word. It should be noted that this task does not give any experimenter-imposed organizational input. The cue words are related to each other in a class inclusion hierarchical structure as illustrated in Fig. 1. The concepts of interest are the Remote Superordinate (RS), the Close Superordinate (CS), and three specific terms, the Target Noun (N), the Close Cohyponym (CC), and the Remote Cohyponym (RC). Predictions can be made about the probability of recalling the target noun given different cues of varying distance. The predictions are based upon the idea that the semantic distance is represented by the number of links between the target noun and the retrieval cue. When the subject is given the retrieval cue (e.g., cat), the probability Remote Superordinate

Target Noun

(T)

00 FIG.

1. Hierarchical

(RS)

Close

Remte

Cohyponym

Cohyponym

(CC)

CR’3

class inclusion system employed with EMR children.

HIERARCHICAL

ORGANIZATION

IN

EMR

279

CHILDREN

of reaching the target noun (e.g., dog) is a direct function of the distance to the retrieval cue. The predictions originally made by Anderson (1972) and used in this study are:

5.

[P(N

1. P(N 1 CS) > P(N 1 RS), 2. P(N CS) > P(N 1 CC), 3. P(N RS) > P(N RC), 4. P(N i CC) > P(N I RC), 1 RS)-Z’(N 1 RC)] > [P(N 1 CS)-P(N

1 CC)].

The first prediction, for instance, would read: the probability of recalling the target noun, given the close superordinate as a cue, will be greater than the probability of recalling the target noun, given the remote superordinate as a cue. The purpose of the present study is to determine the extent to which educable mentally retarded (EMR) children make functional use of a hierarchical class inclusion system in a memory retrieval task that does not have experimenter-imposed input organization. Most of the existing literature suggests that EMR children will not evidence hierarchical organization to the extent that the nonretarded children in the Steinberg and Anderson study (1975) did. METHOD

Subjects Collection ofnormative data. The concepts and pictures were shown to two samples: 18 four-year-old nursery school children and 23 elementary age children in EMR classes. The EMR children had a mean IQ of 63.0, MA of 62.4 months, and chronological age (CA) of 126.0 months. Main study. The main study consisted of three samples: 15 EMR elementary age children from District A, 19 EMR elementary age children from District B, and 20 EMR high school age children from District B. All 54 children were in self-contained EMR classes. The IQ, MA, and CA data for these subjects are presented in Table 1. Materials Collection of normative data. It was necessary to determine if the concepts and pictures to be used in the study were familiar to the EMR population. The categories of Steinberg and Anderson (1975) listed in Table 2 were tested for familiarity using a looseleaf book of 64 randomly arranged plastic covered pages 28.0 x 21.5 cm with two outline drawings per page. The booklet contained three drawings each of the target and close cohyponym concepts and two drawings each of the remote cohyponym concepts. Each page had an outline drawing of the noun and a distractor. The subject was instructed to point to the picture of the named

280

BENDER

AND JOHNSON

TABLE 1 SAMPLE CHARACTERISTICSOF EMR SAMPLE

IQ

District A (elementary) District B (elementary) District B (high school) All subjects

MA (months)

CA (months)

M

SD

M

SD

N

M

SD

15

64.8”

9.8

84.7b

14.8

131.4’

16.2

19

60.1

6.0

91.9

10.2

153.6

14.2

20 54

61.6 62.2

12.0

116.9 98.8

22.8

189.3 158.1

11.5

a IQs do not vary significantly, Fo,S,, = 1.04, p > .05. b MAs vary significantly F,,,,, = 17.8, p < .Ol. Duncan’s multiple range test shows the two elementary samples do not vary significantly, while the high school sample is significantly different, p < .Ol. c All CAs vary significantly, F,,,,, = 78.4, p < .Ol. The CA means are significantly different from each other as revealed by Duncan’s multiple range test, p < .Ol.

concept or to indicate he did not see it. The concepts were first given to four-year-old nursery school children and the results showed that the mean proportion of concepts correct for specific terms (i.e., target, close cohyponym, and remote cohyponym), close superordinates, and remote superordinates, respectively, were 99, .91, and .98. From the feedback the subjects gave, it was decided to change two of the pictures slightly and keep the concept names the same. The concepts were then shown to 23 EMR children in a similar manner. It was found that the mean proportion of concepts correct for specific terms, close superordinates, and remote superordinates were, respectively, .99, .97, and 99. Main study. The eight target nouns (Table 2) plus two distractor drawings (purse and book) and two practice drawings (bird and house) were placed in a 1Zpage looseleaf booklet with one picture on each 28.0 x 21.5-cm page. There were two blocks of five pictures each; a block consisted of four randomly assigned target pictures and one distractor picture. Subjects were shown the pictures in either Block A or Block B first in a counterbalanced order. The retrieval cues (i.e., the names in Table 2) for each block were put in four different randomization orders. Subjects were randomly assigned to the two counterbalanced block orders and the four randomization sequences of retrieval cues. This was done in order to reduce intercategory interference and cue order effects. Procedure Each child was tested individually. going to play a picture remembering

The experimenter said: “We are game. First we will look at some

-

E

Dog

Animal Clothes

Spoon

Apple Nurse Blocks

Car

Clock

Eating utensils

Food People Toys

Vehicles

Measurement

Shirt

Target picture

Category

Wristwatch

Bus

Banana Queen Tinkertoys

Fork

Cat Jacket

Close cohyponym

MATERIALS

TABLE

2

Ruler

Airplane

Hot Dog Policeman Doll

Plate

Hippopotamus Pants

Fruit Lady Something you build things with Something that runs on the road Something that tells time

Pet Something you wear on the upper part of your body Silverware

Close superordinate

EXPERIMENT

Retrieval cue

IN THE

Remote cohyponym

EMPLOYED

Something that takes you someplace Something that uses numbers

Something we put on the table at meal time Food Person Toys

Animal Clothes

Remote superordinate

282

BENDER

AND

JOHNSON

pictures in this book. Then I will close the book and tell you some words. You tell me which picture the word makes you think of. Let’s try some out.” After the subject looked at the two practice drawings and named them, the experimenter closed the book and said: “Which picture did you see that makes you think of a -?” with one of the five practice concepts inserted in the blank (bird, building, airplane, house, things that fly). The experimenter corrected the child if he was wrong or praised him for understanding the rules. When the child understood the task, the experimenter proceeded to turn the five pages of Block A (or Block B) while the child named each target drawing. If he misnamed the drawing, he was given the correct label. Then the book was closed, and the experimenter said, for each of the 20 cue words in the block: “Which picture did you see that makes you think of a -?” A correct response was naming the target word relevant to the category the retrieval cue came from. Whether or not he was correct the child was reinforced with a “Good” after each response. RESULTS

The mean proportion of picture names correctly recalled in the two block orders and four cue randomization orders were submitted to a two-way analysis of variance for each cue. Results revealed no significant main effects or interactions for any of the five cues, (F range .04 to 1.58, df 3,43 (cue order) and I ,46 (block order): p > .05). Thus, all data were combined for the subsequent samples versus cues analysis of variance. Data were submitted to a randomized complete block analysis of variance design. The main effect for samples was not significant, F(2,50) = 2.21, p > .05. Cues were found to differ significantly in effecting recall of the name of the relevant picture, F(4,200) = 32.46,~ < .OOl. The mean proportion of pictures correctly recalled for each type of cue is shown in Table 3. The cue most effective in eliciting recall of picture names was the close superordinate, which differed significantly from the other cues as revealed by Tukey’s w test, p < .Ol. The target, remote superordinate, and close cohyponym cues were equally effective in cueing recall; all comparisons were nonsignificant, The remote cohyponym was least effective in cueing recall; Tukey’s w test revealed significant differences when compared with all other cues, p < .Ol. There was a significant interaction between cues and samples, F(8,200) = 3.87, p < .OOl. As can be seen in Table 3, the interaction is due to the District A sample differing from the other two samples on the target and close cohyponym cues. The hierarchical structure of semantic memory was analyzed by the five predictions set forth above. Since the three samples did not vary significantly, all subjects were pooled for this analysis. Four of the five predictions were found to be significantly upheld by Bonferroni f tests (Kirk, 1968). The first and second predictions [PN 1 CS) > P(N 1 RS) and P(N 1

8

0 Steinberg & Anderson,

All EMR subjects ElementaryEMR (District A) Elementary EMR (District B) High school EMR (District B) Normal (CA 6P

Group

1975.

.84 .79 .84 30 .85

.79

.54

.77 .92

Close superordinate

.68

Target noun naming picture

.75 .72

.63

.66

.67

Remote superordinate

Retrieval Cue

.76 .70

.72

.52

.67

Close cohyponym

TABLE 3 MEAN PROPORTION OF PICTURE NAMES CORRECTLY RECALLED AS A FUNCTION OF CUE AND GROUP

SO .40

.45

.25

.4l

Remote cohyponym

284

BENDER

AND

JOHNSON

CS) > P(N ) CC)] were found significant with the experiment-wise probability of a Type I error set at .05 and the comparison-wise probability of such an error at .Ol. The third and fourth predictions [P(N 1 RS) > P(N 1 RC) and P(N 1 CC) > P(N 1 RC)] were significantly confirmed with the experiment-wise cx set at .Ol and a comparison-wise (Yof .002. The fifth prediction was not confirmed. An even more striking confirmation of the predictions is found in Table 4 which shows the frequency with which the comparisons confirmed the hypotheses. In all cases, 60% or more of the subjects confirmed each prediction. DISCUSSION

The results suggest that EMR children were retrieving information stored in a hierarchical class inclusion system. These results would not be predicted from most of the existing literature in mental retardation. There are three probable explanations of why the present findings are discrepant. First, many of the free recall studies (e.g., Rossi, 1963; Spitz, 1973; Stedman, 1963) were done with institutionalized EMR children. In studies where no significant differences in clustering were found, the EMR subjects often were not institutionalized (e.g., Palmer, 1974; Riegel & Taylor, 1974). Institutionalization may have an effect on verbal repertoires and performance. A second factor is that free recall studies usually do not insure that the mentally retarded subject knows all the subordinate and superordinate terms used in the task. In the present study all concepts were familiar, including superordinate terms. A third factor is the use of a paradigm that allows a relatively more direct measurement of a hierarchical class inclusion structure than tasks such as paired associates, free recall, and serial learning. In the Steinberg and Anderson study the target cue (the name of the picture that the children had seen) was the most effective cue for retrieval, while in the present study the CS was the most effective (see Table 3). The target cue less often elicited the correct response, especially with one of FREQUENCV

TABLE 4 WITH WHICH COMPARISONS CONFIRMED PREDICTIONS EDUCABLE MENTALLY RETARDED CHILDREN Confirm

1. 2. 3. 4. 5.

P(N P(N P(N P(N [P(N V’(N

ICS)>P(N IRS) 1 CS) >P(N 1 CC) ) RS) > P(N 1 RC) 1 CC) > P(N 1 RC) 1 RS)-P(N ) RC)l 1 CS)-I’(N 1 CC)1

Equal

FOR

Disconfirm

38 31 48 45

13 18 4 6

3 4 2 3

31

7

16

HIERARCHICAL

ORGANIZATION

IN EMR CHILDREN

285

the elementary samples as indicated by the samples and cues interaction. The best explanation of this seems to be that the EMR subjects did not interpret what they were supposed to do when asked the target retrieval cue in the same way as they interpreted what they were supposed to do when asked the other cues. Since responses to the target cue are irrelevant to the five predictions tested, this difference does not attenuate this study’s conclusion that EMR children store familiar information in a hierarchical class inclusion structure. REFERENCES Anderson, R. C. Semantic organization and retrieval of information from sentences. Journal of Verbal Learning and Verbal Behavior, 1972, 11, 794-800. Anglin, J. M. The growth and word meaning. Cambridge, Mass.: MIT Press, 1970. Bilsky, L., Ross, R. A., & Gilbert, L. Generalization of associative clustering tendencies in mentally retarded adolescents: Effects of novel stimuli. American Journal of Mental Defkiency, 1972, 77, 77-84. Collins, A. M., & Quillian, M. R. Retrieval time for semantic memory. Journal of Verbal Learning and Verbal Behavior, 1969, 8, 240-247. Gerjuoy, I. R., & Spitz, H. Associative clustering in free recall: Intellectual and developmental variables. American Journal of Mental Deficiency, 1966, 70, 918-927. Inhelder, B., & Piaget, J. The early growth of logic in the child. New York: Norton & Co., 1964. Jensen, A. R. A theory of primary and secondary familial retardation. In N. R. Ellis (Ed.), International review of research in mental retardation. New York: Academic Press, 1970. Vol. 4. Kirk, R. E. Experimental design: Procedures for the behavioral sciences. Belmont, Calif.: Brooks-Cole, 1%8. MacMillan, D. L. Facilitative effects of input organization as a function of verbal response to stimuli in EMR and nonretarded children. American Journal of Mentnl Deficiency, 1972, 76, 408-411. Palmer, M. Clustering in retarded and nonretarded subjects: Some basic determinants. American Journal of Mental Dejiciency, 1974, 78, 454-461. Quillian, M. R. Semantic memory. In M. Minsky (Ed.), Semantic information processing. Cambridge, Mass.: MIT Press, l%8. Quillian, M. R. The teachable language comprehender: A simulation program and theory of language. Communications of the ACM, 1969, 12, 469-476. Riegel, R. H., L Taylor, A. M. Comparison of conceptual strategies for grouping and remembering employed by EMR and nonretarded children. American Journal of Mental Dejiciency, 1974, 78, 592-598. Rossi, E. L. Associative clustering in normal and retarded children. American Journal of Mental Dejiciency, 1%3, 67, 691-699. Spitz, H. H. The role of input organization in the learning and memory of mental retardates. In N. R. Ellis (Ed.), International review of research in mental retardation. New York: Academic Press, 1966. Vol. 2. Spitz, H. H. The channel capacity of educable mental retardates. In D. K. Routh (Ed.), The experimental psychology of mental retardation. Chicago: Aldine, 1973. Stedman, D. 3. Associative clustering of semantic categories in normal and retarded subjects. American Journal of Mental Dejkiency, 1963, 67, 700-704. Steinberg, E. R., & Anderson, R. C. Hierarchical semantic organization in 6-year-olds. Journal of Experimental Child Psychology, 1975, 19, 544-553. RECEIVED: June 14, 1977; REVISED: March 17, 1978.