Operational Research Studies
Differential Item Functioning
Description
Examination of differential item functioning (DIF) by accommodation and disability subgroups.
Outcomes
- Identify item characteristics that perform similarly for subgroups regardless of disability or accommodations.
- Generate hypotheses regarding the causes for DIF by accommodation/modification.
A Comparison of the Factor Structure
Description
Comparison of the dimensionality of reading tests in grades 3–8 for students with specific learning disabilities and for those without a disability. This study also will compare the latent structure for students without a disability and those students belonging to 12 other disability types.
Outcomes
- Provide insight into the ways that students with various disabilities and those without perform in comparison to each other.
- Provide information on the effect of disability type on the validity of a student's score.
Experimentally Designed Study to Examine Differential Boost and Predictive Validity
Description
Large experimentally designed study of students with and without reading-based learning disabilities across two grade levels, 4 and 8. This study will use a randomized within-subject design.
Outcomes
- Determine if impact of audio accommodations changes over grade levels and ability groups.
- Determine predictive validity of listening and reading comprehension for both groups.
- Determine if listening and reading comprehension are similar constructs for students without disabilities.