Designing Accessible Reading Assessments Examining Test Items for Differential Distractor Functioning Among Students with Learning Disabilities Kyndra Middleton The University of Iowa [email protected] April 10, 2007
Mar 27, 2015
Designing Accessible Reading Assessments
Examining Test Items for Differential Distractor Functioning
Among Students with Learning Disabilities
Kyndra Middleton
The University of Iowa
April 10, 2007
Designing Accessible Reading Assessments
Purpose of the Study
• To examine whether different distractor choices functioned differentially for students with learning disabilities who did not receive an accommodation, students with learning disabilities who received a read-aloud accommodation, and students with learning disabilities who received an accommodation other than a read-aloud
• To help determine whether a test can be modified for students with learning disabilities by removing a distractor choice while maintaining adequate test validity and information
Designing Accessible Reading Assessments
Instrument Used
• 4th grade English Language Arts assessment from a criterion-referenced statewide test– Operational test data
– Reading (42 MC items)– Writing (33 MC items)
Designing Accessible Reading Assessments
Sample Used
• 30,000 non-LD students sampled from 298,622 students
• 9,056 LD students who did not receive an accommodation
• 4,727 LD students who received an accommodation based on their IEP/504 plan
• 1,371 LD students who received an accommodation based on their IEP/504 plus a read aloud accommodation
Designing Accessible Reading Assessments
Sample Used cont’d
Subgroup Far Below Basic
Below Basic
Basic Proficient Advanced Total Number of Students
No Disability 4% 11% 31% 30% 25% 30,000
Learning Disability—no
accommodation
32% 34% 25% 7% 2% 9,056
Learning Disability—IEP/5
04
35% 38% 23% 4% 1% 4,727
Learning Disability—IEP/504 & read aloud
26% 36% 30% 6% 1% 1,371
Percentage of Students at Each Proficiency Level
Designing Accessible Reading Assessments
Sample Used cont’dReference-Focal Comparisons
Reference Group Focal Group
No Disability (Group 0) Learning Disability—no accommodation (Group 20)
No Disability (Group 0) Learning Disability—IEP/504 (Group 21)
No Disability (Group 0) Learning Disability—IEP/504 & read aloud (Group 22)
Learning Disability—no accommodation (Group 20)
Learning Disability—IEP/504* (Group 21)
Learning Disability—no accommodation (Group 20)
Learning Disability—IEP/504 & read aloud (Group 22)
Note: IEP = Individualized Education Plan* = comparison did not show DIF so was not included in the DDF analyses
Designing Accessible Reading Assessments
Procedure
• Examine items that previously displayed DIF for DDF– DDF: when two groups that have been matched on
ability have different probabilities of selecting a distractor
• Standardized Distractor Analysis (SDA)
– Distinguishes between distractors
– Identifies uniformly and nonuniformly biased distractors
– An extension of standardized p-difference
Designing Accessible Reading Assessments
Procedure Used cont’d
• Equation used to test for DDF:
STD(i) =
• : negligible DDF
• : moderate DDF
• : large DDF
10.SDA05.
05.SDA
10.SDA
s
rsfss
W(i)P(i)PW
Designing Accessible Reading Assessments
Results
• 70% of the items that displayed DIF also displayed DDF
• 100% of DDF occurred with a comparison between the read aloud and some other group
• 64% of the distractors that displayed DDF were in favor of the read aloud group
Designing Accessible Reading Assessments
Option D Difference*(moderate DIF)
-50
-40
-30
-20
-10
0
10
20
30
40
50
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75
Total Score
Diffe
ren
ce in
Perc
en t
F-R
Designing Accessible Reading Assessments
Option B*: large DIF
-50
-40
-30
-20
-10
0
10
20
30
40
50
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75
Total Score
Dif
fere
nc
e in
Pe
rce
nt
F-R
Designing Accessible Reading Assessments
Option B Difference(no DDF)
-50
-40
-30
-20
-10
0
10
20
30
40
50
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75
Total Score
Diffe
ren
ce in
Perc
ent
F-R
Designing Accessible Reading Assessments
Option B: moderate DDF
-50
-40
-30
-20
-10
0
10
20
30
40
50
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75
Total Score
Dif
fere
nc
e in
Pe
rce
nt
F-R
Designing Accessible Reading Assessments
Option C Difference(large DDF)
-50
-40
-30
-20
-10
0
10
20
30
40
50
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75
Total Score
Diffe
ren
ce in
Perc
en
t
F-R
Designing Accessible Reading Assessments
Results cont’dComparison Groups
0-20 0-21 0-22 20-21 20-22 Ite
m
A B C D A B C D A B C D A B C D A B C D 3 *R
R
*R
R
10 + *F
F
+ *F
F 13 + + *F
F
- 25 ++ *F 32 *R
R
- 33 *F
F
+ 34 + *F 45 *R
R
56 *R 64 *R
R
- *R
R
- *R
R
Note: +: moderate DDF in favor of the focal group++: large DDF in favor of the focal group-: moderate DDF in favor of the reference group*R: DIF in favor of the reference group*F: DIF in favor of the focal groupShaded box: Items that did not exhibit DIF
Designing Accessible Reading Assessments
Results cont’d
• 17% that assessed reading standards showed DDF
• 9% that assessed writing standards showed DDF
• No observed pattern across content or cognitive area between groups
Designing Accessible Reading Assessments
Results cont’d
• Item that displayed large DDF was the most difficult item that displayed DIF
• One item displayed DDF in each of the distractors (two favoring the read aloud group and one favoring the non-LD group)
• Item that displayed DDF in two of its distractors was a spelling item– Both were homophones– Additional difficulty caused by read aloud
Designing Accessible Reading Assessments
Conclusions/Future Research
• Measurement dissimilarity between read aloud group and other groups
• Exploratory study: More research needed to determine whether read aloud actually alters test’s validity
• Matched on ability to provide more information at extremes