Cook, L., Eignor, D., Sawaki, Y., Steinberg, J., & Cline, F. (2010). Using factor analysis to investigate accommodations used by students with disabilities on an English-language arts assessment . Applied Measurement in Education , 23 (2), 187–208. https://doi.org/10.1080/08957341003673831

There were three different accommodations conditions: students who received no accommodations, students who received accommodations as specified in their IEP or 504 plan [specified further in study details], and students who received the read-aloud accommodation.

This study used data from a grade 4 English language arts (ELA) test in an unspecified state (U.S.). Samples of 500 were collected for each of the following groups: students without disabilities who took the test under standard administration, students with disabilities who took the test under standard administration, students with disabilities who took the test with the accommodations specified in their IEP or 504 plan, and students with disabilities who took the test using the read-aloud accommodation.

Scores on a state's standards-based English language arts (ELA) assessment were examined. This ELA assessment incorporated content standards in reading and writing. Reading standards: (a) Word Analysis, Fluency, and Systematic Vocabulary Development; (b) Reading Comprehension; and (c) Literary Response and Analysis. Writing standards: (a) Written and Oral English Language Conventions; (b) Writing Strategies, both of which contained only multiple choice items; and (c) Writing Applications, which contained one essay item. The 75 items analyzed included 42 reading-related items and 33 writing-related items.

Single and multi-group confirmatory factor analysis (CFA) supported a single underlying construct for all groups on both reading and writing tests, but additional statistics did not present as clear-cut a picture. The authors nevertheless conclude that there is evidence for equality of factor structure across the four groups.