Ability or Access-ability: Differential Item Functioning of Items on Alternate Performance-Based Assessment Tests for Students with Visual Impairments

Abstract

Introduction

This study investigated differential item functioning (DIF) of test items on Pennsylvania's Alternate System of Assessment (PASA) for students with visual impairments and severe cognitive disabilities and what the reasons for the differences may be.

Methods

The Wilcoxon signed ranks test was used to analyze differences in the scores of the students with visual impairments and severe cognitive disabilities who took the Grade 3–4 or 7–8 Level A PASA compared to matched peers without visual impairments. The students with visual impairments were analyzed as a group and by level of functional vision. Logical analyses of videotaped assessments of the students with visual impairments were conducted to identify potential sources of DIF.

Results

Among the functional vision groups, 17 instances in reading and 22 instances in math were flagged for DIF, with 14 skills in reading and 13 in math emerging as harder for students with visual impairments. The types of items that were significantly different included those involving money, matching, and selecting the smallest. Potential reasons for the differences included students needing a better orientation to test materials; the influence of lucky guesses based on distractor characteristics; and the influence of accommodations, such as the substitution of objects.

Discussion

The results demonstrate the complexity and importance of evaluating the validity of alternate performance-based assessments for students with visual impairments and severe cognitive disabilities. The themes that emerged suggest the need to structure alternate assessment tasks for consistent orientation to materials and to consider closely how accommodations affect the difficulty of the tasks.

Implications for practitioners

Practitioners should consider how the reading progression for their students with visual impairments and severe cognitive disabilities is related to alternate standards and the instruction that is in place to learn concepts that were missed incidentally. Practitioners can help improve alternate assessments by communicating with their states about the types of tasks that are difficult to accommodate in their current format or by requesting guidance in making meaningful accommodations that maintain the intent of the items.

Get full access to this article

View all access options for this article.

References

Camilli

, & Shepard

L. A.

(1994). MMSS: Methods for identifying biased test items (Vol. 4). Thousand Oaks, CA: Sage.

Elliott

S. N.

, & Roach

A. T.

(2007). Alternate assessments of students with significant disabilities: Alternative approaches, common technical challenges. Applied Measurement in Education, 20, 301–333.

Gersten

, & Baker

(2002). The relevance of Messick's four faces for understanding the validity of high-stakes assessments. In Tindal

, & Haladyna

T. M.

(Eds.), Large-scale assessment programs for all students (pp. 49–66). Mahwah, NJ: Lawrence Erlbaum.

Gong

, & Marion

(2006). Dealing with flexibility in assessments for students with significant cognitive disabilities (Synthesis Report 60). Minneapolis: National Center on Educational Outcomes, University of Minnesota.

Hambleton

R. K.

(2006). Good practices for identifying differential item functioning. Medical Care, 44(Suppl. 3), S182–S188.

Johnstone

C. J.

, Thompson

S. J.

, Bottsford-Miller

, & Thurlow

M. L.

(2008). Universal design and multimethod approaches to item review. Educational Measurement: Issues & Practice, 27, 25–36.

Laitusis

C. C.

, Maneckshana

, Monfils

, & Ahlgrim-Delzell

(2009). Differential item functioning comparisons on a performance-based alternate assessment for students with severe cognitive impairments, autism and orthopedic impairments. Journal of Applied Testing Technology, 10(2), 1–33.

Osterlind

S. J.

, & Everson

H. T.

(2009). Differential item functioning (2nd ed.). Thousand Oaks, CA: Sage.

Standards for educational and psychological testing. (1999). Washington, DC: American Educational Research Association.

10.

Stone

, Cook

, Laitusis

C. C.

, & Cline

(2010). Using differential item functioning to investigate the impact of testing accommodations on an English-language arts assessment for students who are blind or visually impaired. Applied Measurement in Education, 23, 132–152.

11.

Thompson

S. J.

, Johnstone

C. J.

, Anderson

M. E.

, & Miller

N. A.

(2005). Considerations for the development and review of universally designed assessments (Technical Report 42). Minneapolis: National Center on Educational Outcomes, University of Minnesota.

12.

Wyver

S. R.

, & Markham

(1999). Visual items in tests of intelligence for children. Journal of Visual Impairment & Blindness, 93, 663–665.

13.

Yovanoff

, & Tindal

(2007). Scaling early reading alternate assessments with statewide measures. Exceptional Children, 73, 184–201.

14.

Zumbo

(2007). Three generations of DIF analyses: Considering where it has been, where it is now, and where it is going. Language Assessment Quarterly, 4, 223–233.