1. National Accessible Reading Assessment Projects Examining Background Variables of Students with Disabilities that Affect Reading Jamal Abedi, CRESST/University of California, Davis Seth Leon and Jenny Kao, CRESST/University of California, Los Angeles

2. National Accessible Reading Assessment Projects Examining Background Variables of Students with Disabilities that Affect Reading The reauthorization of the Individuals with Disabilities Education Act (IDEA) demands equity and accountability in education for the approximately 6.5 million children and youth with disabilities in the United States (U.S. Department of Education, 2004) In the 2003-2004 school year, almost half of all students with disabilities were in regular classrooms for 80 percent or more of the school day (U.S. Department of Education, 2005) Including these students into assessments requires first having a valid and reliable measure of their knowledge and skills

3. National Accessible Reading Assessment Projects Focus on Reading Among the content areas, reading is of greater importance. Literature shows lower performance on academic achievement tests for students with disabilities (SD). Students with disabilities usually fail at higher rates than other students, even on tests of basic skills for graduation (Heubert, 2000) These students perform significantly lower than students with no apparent disabilities (Abedi, Leon, & Mirocha, 2003; Thurlow, et. al., 2000; Tindal, et. al, 2000; Ysseldyke et al., 1998) In 1998, data from fourteen states revealed that students with disabilities consistently failed state graduation tests at rates 35 to 40 percentage points higher than those for non-SD (Ysseldyke et al., 1998)

4. National Accessible Reading Assessment Projects Factors contributing to performance-gap between SDs and non-SDs There are many factors that contribute to performance-gap between SDs and non-SDs This paper focuses on the background factors that affect reading This paper uses the term background in a broader sense to include both students background variables and background variables related to the assessment We focused on students background knowledge and Test format

5. National Accessible Reading Assessment Projects Differential pattern of performance across SD/non-SD categories We examined the possibility of differential impact of these variables on the reading performance of students with disabilities The results of this study along with the findings of other studies showed differential impact across SD/non-SD categories There are many different forms of detecting item bias (Matlock-Hetzel, 1997; ONeal, 1991)

6. National Accessible Reading Assessment Projects Data Source The data were obtained for the 1997-1998 academic year from a state with a large number of ELLs and students with disabilities Included item-level information on grades 3 and 9 students responses to Stanford 9 Reading Comprehension (RC) and Word Analysis (WA) Multiple-choice items in two reading subscales (RC & WA) were selected for this study. Analyses were conducted for grade 3 and grade 9 students Students in higher grades may have more difficulty with reading

7. National Accessible Reading Assessment Projects Statistical Design Logistic regression approach was used to examine the possibility of differential distractor functioning (DDF) across the SD and non-SD categories Responses were grouped into two categories (1) students who selected the most common distractor, and (2) students who selected one of the two less common distractors This indicator of distractor selection was used as the criterion variable SD status, ELL status and the total standardized Z-score on the subscale being analyzed were used as predictors Odds Ratios (OR) of selecting the less common distractors as compared with the most common distractor were computed

8. National Accessible Reading Assessment Projects Results Reading Comprehension, Grade 3 The large majority of the items exhibit DDF based on reading comprehension ability Of the 54 items, 46 showed significant DDF on the ability measure A significant odds ratio greater than one indicates that SDs were less likely to choose the most commonly chosen distractor

9. National Accessible Reading Assessment Projects Results Reading Comprehension, Grade 9 The large majority of the items exhibit DDF based on reading comprehension ability Of the 54 items, 46 showed significant DDF Significant DDF for SDs suggests that SDs are generally less likely to choose the most commonly chosen distractor when compared to non-SDs Results show that a substantial number of items exhibit DDF for SDs even when controlling for reading comprehension ability It also appears both for SDs that there are more items in grade 9 that exhibit DDF as compared to grade 3 on the reading comprehension subscale

10. National Accessible Reading Assessment Projects Word Analysis, Grade 3. Just over one half (16 of 30) of the items exhibit DDF based on the word analyses ability. This was a considerably smaller proportion as compared the RC subscale in which 46 of 54 items showed significant ability DDF A significant DDF for SDs suggest that they were generally less likely to choose the most commonly chosen distractor when compared to non-SDs

11. National Accessible Reading Assessment Projects Word Analysis, Grade 9 Of the 30 items, 22 exhibited DDF based on reading comprehension ability The odd rations for SDs were most often greater then one The grade 9 results show that a substantial number of items exhibit DDF for SDs even while controlling for reading comprehension ability Similar to the RC results, SDs had more items in grade 9 that exhibited DDF as compared to grade 3 on the WA subscale

12. National Accessible Reading Assessment Projects Conclusion Findings of this study provide evidence that in addition to test content other factors may contribute to the performance-gap between SDs and non-SDs Controlling for these factors that are not related to content being assessed may help test developers provide more accessible and more valid assessments for students with disabilities

13. National Accessible Reading Assessment Projects Limitations This study did not differentiate between different categories of disabilities Student performance across different categories of disabilities may be quite different and these factors may affect their performance quite differently We could not include other test characteristics (such as type of items, fatigue and frustration factors, graphic layout, and size and type of font) that may be considered as extraneous or nuisance variables and may impact performance students with disabilities

14. National Accessible Reading Assessment Projects Background knowledge (Nicole Strangman and Tracey Hall National Center on Accessing the General Curriculum) Students who lack sufficient background knowledge may struggle to access, participate, and progress throughout the general curriculum The terms background knowledge and prior knowledge are generally used interchangeably Prior knowledge and background knowledge include dimensions such as conceptual knowledge, metacognitive knowledge, subject matter knowledge, strategy knowledge, personal knowledge, and self- knowledge

15. National Accessible Reading Assessment Projects Background knowledge (continues…) There is a well established correlation between prior knowledge and reading comprehension (Langer, 1984; Long, Winograd, & Bridget, 1989; Stevens, 1980) Irrespective of students reading ability, high prior knowledge of a subject area or key vocabulary for a text often means higher scores on reading comprehension measures (Langer, 1984; Long et al., 1989; Stevens, 1980) After controlling for reading ability in the sample, a significant effect of prior knowledge building on reading comprehension was observed (Stevens, 1982; Dole et al., 1991 & Graves et al., 1983)

16. National Accessible Reading Assessment Projects Student characteristics Weisberg (1988) claims that students with disabilities, as a group, demonstrate a considerable over reliance on prior knowledge when text material is inconsistent with their preconceptions This raises another issue, which is whether a students educational group or disability status influences the effectiveness of prior knowledge activation strategies A few of these studies with students with learning disabilities revealed differences in responsiveness to prior knowledge activation across educational groups (Carr et al., 1996; Langer, 1984; Pflaum et al., 1982; Carr et al., 1996; Croll, Idol-Maestas, Heal, & Pearson, 1986; Pflaum, Pascarella, Auer, Augustyn, & Boswick, 1982; Walraven et al., 1993)

17. National Accessible Reading Assessment Projects Overall Summary/Conclusion Many factors contribute to the performance- gap between SDs and non-SDs Among these factors, background variables may have substantial impact on SDs performance To have a more valid and reliable test and at the same time more accessible assessment for SDs, these factors and their level of contribution must be identified and controlled

18. National Accessible Reading Assessment Projects For more information contact: Jamal Abedi: jabedi@ucdavis.edu (530) 754-9150