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administering the KTEA-3 together with tests of cognitive ability to samples of children with ADHD and samples of children with comorbid ADHD and SLD will provide useful information to clinicians who work with such children.

PART TWO: NEW COMPOSITE SCORES, SPECIAL

CONSIDERATIONS, AND ONGOING RESEARCH

Interpretation and Use of Three New Composite Scores

Included with this book are normative tables for generating three new composite scores. The new composite scores include four Dyslexia Index scores, two for the KTEA-3 and two for the WIAT-III, and a new KTEA-3 Oral Reading Fluency composite. The specific tables provided as Digital Resources are listed in the Don’t Forget box.

Don’t Forget

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New Scores Tables Included as Digital Resources With This Book

For the Dyslexia Index Scores, the following tables are provided for the KTEA-3 and

the WIAT-III:

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Grade-Based and Age-Based Composite Standard Scores

Bands of Errors (95%, 90%, 85% Confidence Intervals) for Grade-Based Standard Scores and Age-Based Standard Scores

Split-Half Reliability Coefficients for Subtests and Composites by Grade and by Age

Reading/Writing Disorder Sample Mean Scores

For the KTEA-3 Oral Reading Fluency composite score:

Grade-Based and Age-Based Composite Standard Scores

Bands of Errors (95%, 90%, 85% Confidence Intervals) for Grade-Based Standard Scores and Age-Based Standard Scores

Composite Score Comparisons for KTEA-3 Oral Reading Fluency Composite versus KTEA-3 Decoding Composite Score: Significance and Frequency of Standard Score Differences by Grade and by Age

Split-Half Reliability Coefficients for Subtests and Composites by Grade (3–12) and by Age (8–25)

Dyslexia Index Scores

The Dyslexia Index scores were designed to provide theoretically sound and research-based composite scores that maximize clinical sensitivity for identifying young children at-risk for dyslexia as well as students and adults who may have dyslexia. However, no single score is su cient to identify or diagnose dyslexia.

280 ESSENTIALS OF KTEA™-3 AND WIAT®-III ASSESSMENT

Best practice for identifying dyslexia typically involves consideration of developmental, medical, and family history as well as a comprehensive evaluation of oral language, cognitive processing abilities, and academic skills. Dyslexia is best identified by a qualified professional based on a thoughtful synthesis of all available quantitative and qualitative evidence.

As specified in the international definition of dyslexia adopted by the IDA and NICHD (see Don’t Forget box), the core symptoms of dyslexia typically include poor spelling, basic reading (accuracy and/or fluency), decoding, and phonological processing. In addition to poor phonological awareness, research indicates that poor letter knowledge and rapid automatic naming (naming facility) are core symptoms or predictors of dyslexia before children have begun reading (grades K and 1).

The most powerful predictors of reading di culty in the earliest grades are letter knowledge, rapid automatic naming, and phonological awareness

22222222111111111 (Kirby, Parrila, & Pfei er, 2003; Schatschneider & Torgesen, 2004). Measures of letter-name knowledge (early kindergarten) or letter-sound knowledge (later kindergarten) are excellent predictors of early word reading di culties (Schatschneider & Torgesen, 2004). In addition, slow naming speed, especially in combination with phonological di culties, predicts later reading di culties (Kirby, Parrila, & Pfei er, 2003). Naming speed is important as a prerequisite for developing orthographic skill (Wolf & Bowers, 1999). As Bowers (1996, p. 1) explained, “naming speed influences the ability to learn the orthographic pattern of words.” Since later reading development relies upon orthographic skill, naming speed is predictive of later reading skill. Hence, both phonological awareness and naming speed measures

CLINICAL APPLICATIONS 281

are useful for the early identification of children at-risk for dyslexia. However, once children begin reading, the best diagnostic indicators of dyslexia are measures of decoding fluency and text reading fluency, not measures of phonological awareness and rapid automatic naming (Schatschneider & Torgesen, 2004).

Based on this research, the KTEA-3 Dyslexia Index for grades K-1 includes measures of naming facility, phonological awareness, letter knowledge, letter-sound correspondence, and word recognition. The WIAT-III Dyslexia Index for grades K-1 includes measures of phonological awareness, letter knowledge, letter-sound correspondence, word recognition, and the orthographic loop. Both composites scores may be considered highly reliable and theoretically sound. The primary di erence between these composites is that only the KTEA-3 includes a measure of rapid automatic naming/naming facility and only the WIAT-III includes a measure of the orthographic loop (early spelling of phonemes and words). The KTEA-3 includes a more comprehensive measure of phonological processing skills than the WIAT-III, which also contributes to a longer administration time (6–8 minutes longer) for the KTEA-3 Dyslexia Index as compared to the WIAT-III Dyslexia Index for grades K–1.

Based on the core symptoms agreed-upon by the international definition of dyslexia (see Don’t Forget box) and the associated research support, the KTEA-3 Dyslexia Index for grades 2–12 includes measures of oral word reading fluency, decoding, and spelling. The WIAT-III Dyslexia111111111 Index for grades 2–12 includes measures of oral contextual reading fluency, decoding, and spelling. The primary di erence between these composites is with the oral reading fluency measures: the KTEA-3 includes single word reading fluency whereas the WIAT-III includes passage reading fluency. The administration times are comparable for both composites (12–15 minutes).

The composite structures and estimated administration times for the four new Dyslexia Index scores are summarized in Rapid Reference 4.27. Any of the four Dyslexia Indexes may be administered in 20 minutes or less on average.

As shown in Table 4.4, the split-half reliability coe cients for the new Dyslexia Index scores are excellent, and the index scores showed large e ect sizes in di erentiating students with reading/writing disabilities from their normally achieving peers. Generally, reliabilities of .90 or higher support the use of a score for making educational decisions.

KTEA-3 Oral Reading Fluency Composite

The new KTEA-3 Oral Reading Fluency (ORF) composite is designed to measure oral reading fluency of single words and pseudowords. This new composite score is especially useful for two purposes: (1) identifying students who exhibit weaknesses in oral reading fluency but not in silent reading fluency; and (2) facilitating a direct comparison of a student’s basic reading accuracy and basic reading fluency by comparing the KTEA-3 ORF composite score with the KTEA-3 Decoding composite score.

282 ESSENTIALS OF KTEA™-3 AND WIAT®-III ASSESSMENT

Rapid Reference 4.27

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Composite Structure of the Dyslexia Index Scores

Table 4.4 Split-Half Reliability Coefficients and Clinical Validity Data for the New Dyslexia Index scores

Note: All scores from the Reading/Writing Disorder groups were significantly lower ( p < .01) than those of the nonclinical matched control groups. N-count for the Reading/Writing Disorder group at Grades K–1 was insu cient for clinical group comparison; for this reason, group means and e ect sizes were based on a sample of students in grades 1–4, ages 6–10 (KTEA-3 n = 20; WIAT-III n = 36).

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The Decoding composite provided in the KTEA-3 measures oral reading accuracy of single words and pseudowords. The main di erence between LWR and WRF, and between NWD and DF, is that LWR and NWD are untimed measures and WRF and DF are speeded tasks. Clinically useful information may be obtained by comparing analogous measures of basic reading accuracy and basic reading fluency. Many struggling readers exhibit poor performance in both accuracy and fluency. Other struggling readers exhibit poor performance that is specific to fluency or only detected on a speeded measure. For this reason, score comparison tables are provided as Digital Resources for comparing the ORF and Decoding composite scores.

The new ORF composite di ers from the Reading Fluency composite provided in the KTEA-3 (see Rapid Reference 4.28). The Reading Fluency composite provides a measure of reading fluency that includes silent contextual reading fluency as well as oral reading fluency of single words and pseudowords. This composite is useful for measuring broad reading fluency deficits that include silent and oral reading as well as contextual and single word reading.

Rapid Reference 4.28

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KTEA-3 Oral Reading Fluency (ORF) Composite Structure

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Related KTEA-3 Composites