THE STRUCTURE OF THE STANFORD DIAGNOSTIC READING TEST I N RELATION TO

THE ASSESSMENT OF LEARNING-DISABLED PUPILS DONALD A. LETON

University of Hawaii

This study attempted primarily to determine whether several types of reading disability might be discernible in the diagnostic reading profiles of learning-disabled (LD) pupils. A secondary purpose was to evaluate the Stanford Diagnostic Reading Test in relation to the assessment of the reading difficulties of LD pupils. Various types of reading disabilities related to the etiology and characteristics of LD pupils can be hypothesized. Their reading disabilities may be modality referenced, e . g., aural-oral or visual motor, or they may be referred to associational or memory deficits. The types of achievement problems that are manifested by children with neurogenic learning difficulties have not been identified as yet.

The educational classification of the LD pupils in this study was based on pediatric-neurological, psychological, educational, and speech-language examina- tions. These were conducted primarily a t the Learning Disabilities Clinic of the Hawaii State Department of Health. Profiles from the Wechsler Intelligence Scale for Children and the Illinois Test of Psycholinguistic Abilities are presented in Figs. 1 and 2. These ability test data also have been analyzed in two previous reports (Leton, 1972a, 1972b).

Fro. 1. Profile of WISC Scale Scores for 166 LD Pupils, Average Age 11-7 Years.

Inf Com Ari S i m Voc D.S. VSS PC PA BD OA Cod PSS Tat I

.1 \ 1

Means 6-18 7.36 7.12 7.05 6.53 6.61 6.96 9.00 8.92 8.93 8.06 8.13 8.60 8.781 SD 2.42 2.80 3.19 3.21 3.01 2.35 2.21 2.67 2.79 3.17 2.90

STRUCTURE OF THE STANFORD DIAGNOSTIC READING TEST 41

The intelligence deficits that are reflected in the WISC profile include: (1) verbal associational; (2) short-term auditory memory; (3) motor associational; and (4) form perception. The lower profile for the subtests in the verbal section of the test indicates a basic difficulty in the development of verbal intelligence. A majority of LD pupils manifest normal visual-analytic abilities, as required for the Picture Completion, Picture Arrangement, and Block Design subtests. LD pupils are heterogeneous with respect to their intelligence deficits and achievement dif-

FIG. 2. Profile of ITPA Subtest Scores and WISC Mental Age Scores for 167 LD Pupils.

ficulties. One of the salient features in their test performances is a difficulty with motor-associational tasks. This is reflected in the achievement difficulties, in their acquisition of scripting and drawing skills, and in their reading development.

In addition to the intelligence deficits previously mentioned, some LD pupils may show difficulties in processing positional and sequentjal informat,ion. These are uniquely important in the basic procedures of reading, scripting and computing. Their tendency to make reversal, rotation and transposition errors occurs jn the mental processing of figural and symbolic materials.

The LD pupils in this study exhibit difficulty with the verbal associative, vocal expressive, visual motor sequencing, and auditory memory-vocal sequencing factors on the ITPA. Their language age scores are consistently lower than their mental age scores on the verbal section of the WISC. There is a possibility that the greater deficits in linguistic abilities may be due in part to pidgin dialect, rather than solely to neurologic impairments of language functions.

42 DONALD A. LETON

METHOD The Stanford Diagnostic Reading Test, Level I, (SDRT) was administered to

166 LD pupils in the elementary and intermediate school classes in the Honolulu School District.' This represented about 80 yo of the enrollment for these classes for the fall 1972 semester. The pupils for whom the SDRT data were obtained had been enrolled in the LD special education program for a minimum of three semesters; the average length of enrollement was 2.6 years. Pupils who were newly enrolled in the spring and fall semesters in 1972 and pupils who were returned to regular edu- cation classes were not included in this survey.

The summary results of the Stanford Diagnostic Reading Test are presented in Table 1.

Consistent age-grade increases are observed in the raw scores for the seven subtests for grades 3 through 7. The eighth-grade pupils obtained relatively lower scores, which may be attributed to several selection factors. As the number of identified LD pupils increased they could not all be accommodated in the available c1assrooms, so those with the most severe achievement problems received priority.

(LEVEL I) FOR 166 LEARNINGDISABLED PUPILS TABLE 1. RAW SCORE AND STANINE SCORE MEANS ON STANFORD DIAQNOSTIC READING SUBTESTS

Grade Levels 3 4 5 6 7 8 9 Total

Sample Sizes 7 25 35 56 21 12 10 166 Age Levels 9-1 9-9 11-1 11-8 13-1 14-0 15-0 11-7

Subtests Raw Score Means

Reading Comprehension 21.1

Auditory Discrimination 22.5

Beginning & Ending Sounds 22.4 Blending 16.2 Sound Discrimination 12.2

Rdg. Comp. Grade Score (2.1)

Vocabulary 18.1

Syllabication 8.7

21.4 25.9 16.7 21.3 27.0 31.9 9.0 11.2 22.7 25.4 19.3 22.7 13.8 17.1

(2.1) 2.5

27.8 20.3 31.7 11.3 26.3 24.2 18.4

2.6

30.3 26.1 24.1 23.7 31.1 24.1 12.3 10.5 26.3 26.6 23.9 19.5 15.9 11.2

2.7 2.5

30.5 28.1 31.6 11.6 27.5 19.2 13.6

3.0

26.5 21.0 30.0 10.9 25.5 22.1 16.1

2.5

Stanine Means Readingcomprehension 2.4' 1.7 2.2 2.5 3.1 2.0 3.6 2.4 Vocabulary 3.4 2.1 3.2 3.0 4.2 3.7 5.4 3.3 Auditory Discrimination 2.7 2.9 3.6 3.9 3.7 2.5 3.1 3.5 Syllabication 2.5 2.0 3.0 3.2 3.1 2.9 3.4 2.9 BeginningdzEndingSounds 2.5 2.1 2.9 3.2 3.0 3.0 3.6 3.0 Blending 2.8 2.4 3.0 3.6 3.1 2.8 2.9 3.1 Sound Discrimination 2.4 2.0 2.8 3.0 2.6 1.6 2.3 2.6

*Stanine scores for third-grade pupils derived from. test norms for pupils at or below 3.5 grade level.

'The cooperative assistance of the teachers of the LD classes who administered the test, of the Special Education supervisors Mrs. L. McCartney and Mrs. R. Nishikawa who coordinated the testing, and of the district administrators who endorsed this study is acknowledged gratefully.

STRUCTURE OF THE STANFORD DIAGNOSTIC READING TEST 43

Vocabulary

Auditory Discr iminat ion

S y l l a b i c a t i o n

With the transfer from elementary schools to junior high schools the achievement skills of LD pupils are reevaluated. The pupils whose achievement skills are ade- quate for enrollment in regular classes are discontinued from special education, and their LD classification is rescinded. These selection and deselection factors explain some of the inconsistencies in the scores at various grade levels.

The LD pupils’ limitations in reading achievement are reflected in the grade- equivalent scores for reading comprehension. The numbers of pupils at the third-, eighth-, and ninth-grade levels are not sufficient for reliable comparisons among grade levels; however, 110 of the 166 pupils obtained grade scores between 1.7 and 3.4 on the Reading Comprehension subtest.

The minor increases in the raw score means at succeeding grade levels reflect the persistence of the LD pupils’ reading difficulties through the elementary grades. The only subtest in which a consistent increase leads to a significant improvement is the Auditory Vocabulary subtest. This does not indicate an improved reading skill, but rather an improvement in oral vocabulary.

Fro. 3. Profile of Means and Standard Deviations of Stanine Scores on Stanford Diagnostic Reading Tests.

\

‘*., I . I

\. I

t---+-+ I‘

I‘

t 4 ,r N a166 LD Pupfls

Comprehension

Beginning & Ending Sounds

Blending

Sound Discr iminat ion 11;’

S t a n i n e s

The profile of stanine scores is presented in Fig. 3. The pupils’ difficulties with verbal-associational learning are reflected in the low score for Reading Comprehen- sion. Their low score in the Sound Discrimination subtest is not due to auditory difficulties. Rather, the subtest requires the pupil t o subvocalize the stimulus word and the test words and then to determine which of the test words is vocalized in a manner similar to the stimulus words. The LD pupils’ low score is due to their basic inability to recognize and vocalize the test words, particularly the vowel elements of the words, rather than to an inability to discriminate sounds.

The authors of the SDRT (Karlsen, Madden, & Gardner, 1966) hypothesize that auditory discrimination, identification of beginning and ending sounds, sound

44 DONALD A. LETON

discrimination, syllabication, and blending are hierarchical subskills in word recog- nition and that word recognition and auditory vocabulary are subordinate to reading comprehension. A dendrograph of the hypothesized structure of the SDRT is presented in Fig. 4.

FIQ. 4. Hypothesized Structure of the Stanford Diagnostic Reading Test,

Reading Comprehension

Word Aud it ory Recognition Vocabulary

The notion that the skill of word recognition evolves from various subskills prevails rather widely. If analyses of the SDRT data support the authors’ theories then the diagnostic value of the test would be validated, and remedial instruction could be planned in accordance with the subtest profiles.

The subtest scores for the 166 LD pupils were intercorrelated, and a hier- archical cluster analysis was performed (Johnson, 1967) to investigate the relation- ships among the subtests. The connectedness of the subtests is displayed in the dendrograph in Fig. 5.

STRUCTURE OF THE STANFORD DIAGNOSTIC READING TEST 45

Fro. 5. A Dendrogra h that Illustrates the Hierarchical Clustering of SDRT Subtest {cores, Based on a Criterion of Connectedness.

.4

* 5

.6 (0 al 5 r(

. 7 [I] :

5 .8

-0 al u 0 al

0 u

09

I r

b, @

It is obvious that the word recognition subskills of the LD pupils we not ar- ranged hierarchically in the hypothesized order. Several possible conclusions may be stated: (1) the theory about the order of the word-recognition subskills may be incorrect; (2) the specific SDRT subtests may be inconsistent with the theory, even for average or skillful readers, and (3) the intellectual deficits of LD pupils may exert specific disordering influences on the hierarchy to produce the obtained structure.

The interrelationships among the SDRT subtests also were studied in a factor analysis of the correlation matrix. The factor analysis utilized principal compo- nents procedures, with squared multiple correlations inserted for communality es- timates, and varimax procedures for the rotation of factors with positive eigenvalues. The rotated factor matrix is presented in Table 2.

46 DONALD A. LETON

TABLE 2. SDRT SUBTEST LOADINGS AND COMMUNALITIES IN TEE ROTATED FACTOR MATRIX

Subtests I I1 I11 hs

Reading Comprehension Auditory Vocabulary

38 .42 .63 .72 16 .50 .20 .32

Auditory Discrimination .38 .51 .26 .47 Syllabication Begin. & End. Sounds Blending Sound Discrimination

Factor Values Percent of Variance

.47 .28 * 29 .39

.36 .35 .65 .68

.66 .27 .57 .72

.53 .34 .36 .53

1.26 1.07 1.46 3.79 18 16 21 55

The Syllabication and Sound Discrimination subtests received primary loadings on the first factor; the Blending subtest received a high secondary loading. These subtests require word recognition as a prerequisite skill and test the pupil’s ability to analyze the phonetic constituents of words. The similarity of the tasks for the three subtests is reflected in the following restatements of instructions: “Identify the ‘sounds’ in the first syllable” (Syllabication), “Identify the sounds that would be used for the oral production of the word” (Blending), and “Identify which of the test words, if vocalized, would include a sound similar to the designated part of the printed stimulus word” (Sound Discrimination). Each of these subtests requires an internal, “silent” analysis to locate the vocalic elements of the unvoiced words. This factor is identified as an ability to recognize words and analyze their phonetic el+ ments.

The Auditory Vocabulary and Auditory Discrimination subtests received pri- mary loadings on the second factor. In the Vocabulary subtest the stimulus sen- tence and response words are read to the pupil; in the Auditory Discrimination sub- test the paired stimulus words are read to the pupil. The two response tasks for these subtests are different. They require: (1) selection of the word for which meaning was given, and (2) indication of the similarities of the paired words in their initial, final or medial sounds. This factor is identified as an auditory associative ability and is based on aural receptive skills.

The third factor is defined by the Reading Comprehension, Blending, and Begin- ning- and Ending-Sounds subtests. Although the test tasks appear to be different they require visual processing and verbal mediation of visually presented materials. Success on the Comprehension subtest requires the reconstruction of information contained in the test paragraphs; success on the Beginning- and Ending-Sounds subtest requires a preliminary recognition of the correct noun-word for a pictured object and an identification of the printed letters that indicate the beginning and ending sounds of the word. The third factor is identified as visual processing and verbal mediation.

The three factors account for 55 %of the total test variance. The residual 45 % of the variance is unreliable for the diagnosis of LD pupils’ reading skills. The residual variance possibly may bear some systematic relationships to the intellectual deficits of LD pupils.

STRUCTURE OF THE STANFORD DIAGNOSTIC READING TEST 47

DISCUSSION The SDRT emphasizes several kinds of phonetic analysis and aural-oral pro-

cessing of phoetjc elements within words. With this orientation it does not assess the form perception, motor association, visual rotation, and transpositional diffi- culties of LD pupils. The value of the SDRT for the diagnosis of LD pupils’ reading difficulties therefore is questionable. To the extent that the scores reflect their word recognition and phonetic analysis skills, aural receptive skills, and visual processing and oral mediation skills, the test may have some value.

The factor analysis of the SDRT disclosed three achievement skills. The un- reliable variance in the domain of LD pupils’ scores, however, may produce as much variability as the LD pupils can produce reliably in the exercise of their reading skills. The hierarchical clustering procedure employed in this study provides a critical analysis of the hypothesized structure of the test. The cluster analysis, however, failed to identify different subtypes of reading problems.

University of Hawaii at Manoa 1776 University Avenue Honolulu, Hawaii 96822

REFERENCES JOHNSON, S. C. Hierarchical clustering schemes. Psyehometrika, 1967, 32, 241-264. KARLSEN, B., MADDEN, R., & GARDNER, E. Manual, Stanford Diagnostic Reading Test. New York:

LETON, D. A. A factor analysis of ITPA and WISC scores of learning-disabled pupils. Psychology

LETON, D. A. Discriminant analysis of WISC profiles of learning-disabled and culturally-disad-

Harcourt, Brace & World, 1966.

in the Schools, 1972, 9, 3136. (a)

vantaged pupils. Psychology in the Schools, 1972,9,303-308. (b)

THE RELATIONSHIP OF THE WISC TO THE REVISED ITPA IN EMOTIONALLY DISTURBED CHILDREN’

I. LOUIS YOUNG AND PETER H. CORMACK

Convalescent Hospital for Children Rochester, N . Y.

The diagnosis of specific learning disabilities is a major part of the function of the school and the clinical child psychologist. Numerous approaches are utilized (McCarthy & McCarthy 1969), and children often are subjected to extensive diagnostic study in attempts to understand the nature of their problem. The tests utilized in these evaluations are thought to assess various dimensions of cog- nitive and emotional functioning that theoretically relate to school learning ability. The eficiency of these time-consuming procedures is questionable, since both p r e vious research and the author’s clinical experience indicate that often there seems to be a good deal of overlap between the data yielded by some of the more frequently used instruments (Garms, 1970). The present study assessed 78 emotionally dis-

1The authors wish to express their appreciation to Dr. Benjamin Hayden of the Astor Home for Children in Rhineback, New York, for providing us with some of the raw data utlieed in this research.