Discrimination Toward Students with Disabilities in University Group Work: A Randomized Vignette Study

Last registered on April 14, 2026
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Pre-Trial

Trial Information

General Information

Title
Discrimination Toward Students with Disabilities in University Group Work: A Randomized Vignette Study
RCT ID
AEARCTR-0018322
Initial registration date
April 10, 2026

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
April 14, 2026, 9:07 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Locations

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Primary Investigator

Name
Michael Palmer
Affiliation
The University of Western Australia
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Other Primary Investigator(s)

Additional Trial Information

Status
On going
Start date
2025-08-01
End date
2028-12-31
Keywords
Behavior, Education, Gender, Other
Additional Keywords
disability, discrimination, university students, group work, vignette experiment
JEL code(s)
J71, I23, C93
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This study examines whether university students show bias when considering working with peers who have disabilities in group assignments.
The study is conducted with undergraduate business students at the University of Western Australia using an online survey. Participants are randomly assigned to evaluate profiles of hypothetical teammates that vary in whether the student has no disability, a physical disability, or is on the autism spectrum. The profiles also vary whether academic performance information is provided and whether the student is male or female. Participants rate their willingness to work with each teammate, as well as expectations about their competence, reliability, and contribution. By comparing responses across these conditions, the study measures whether students are less willing to work with peers with disabilities and whether providing information about academic performance reduces this gap. The findings will help identify the sources of bias in collaborative learning environments and inform policies aimed at improving inclusion for students with disabilities in higher education.
External Link(s)

Registration Citation

Citation
Palmer , Michael . 2026. "Discrimination Toward Students with Disabilities in University Group Work: A Randomized Vignette Study." AEA RCT Registry. April 14. https://doi.org/10.1257/rct.18322-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
Participants complete an online survey in which they evaluate profiles of hypothetical teammates for a university group assignment. The profiles vary whether the student has no disability, a physical disability, or is on the autism spectrum, as well as whether academic performance information is provided and whether the student is male or female. The intervention consists of exposure to these randomly assigned profiles.
Intervention Start Date
2025-08-01
Intervention End Date
2027-12-31

Primary Outcomes

Primary Outcomes (end points)
Willingness to work with the teammate; belief that the teammate will contribute effectively; perceived academic competence; expected reliability (attendance and timely completion of tasks).
Primary Outcomes (explanation)
Each primary outcome is measured as a separate 7-point Likert-scale response to the assigned vignette. Higher values indicate more positive evaluations of the teammate. The outcomes are analysed individually. In addition, a composite index of overall evaluation may be constructed by standardising each primary outcome and taking their average, with signs aligned so that higher values indicate more positive evaluations of the teammate.

Secondary Outcomes

Secondary Outcomes (end points)
Willingness to nominate the teammate as group leader; perceived need for additional effort; preference to switch to a different group.
Secondary Outcomes (explanation)
Each secondary outcome is measured as a separate 7-point Likert-scale response to the assigned vignette. Higher values indicate greater willingness to nominate the teammate as leader, greater perceived need for additional effort, and a stronger preference to switch to another group. The outcomes are analysed individually. In addition, a composite index of secondary outcomes may be constructed by standardising each outcome and taking their average, with signs aligned so that higher values consistently reflect more negative evaluations of the teammate.

Experimental Design

Experimental Design
The study uses a randomized vignette experiment with a 3 × 2 × 2 between-subjects factorial design. Participants are randomly assigned to evaluate a profile of a hypothetical teammate in a university group assignment. The profile varies along three dimensions: disability status (none, physical disability, or on the autism spectrum), presence of an academic performance signal, and gender. Participants rate their willingness to work with the teammate and their expectations about the teammate’s performance across several dimensions.
Experimental Design Details
Not available
Randomization Method
Randomization done by a computer using the Qualtrics survey platform.
Randomization Unit
Individual participant
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
N/A
Sample size: planned number of observations
800-1,500 students
Sample size (or number of clusters) by treatment arms
Approximately equal allocation across 12 treatment arms, with about 65–125 students per arm depending on final sample size.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
The study is designed to detect small-to-moderate effects in the main outcomes. Depending on the final sample size, the minimum detectable effect size for the main comparisons is expected to be in the range of approximately 0.20–0.30 standard deviations with 80% power at the 5% significance level. Larger samples will improve precision for subgroup and interaction analyses.
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
The University of Western Australia Human Research Ethics Committee
IRB Approval Date
2025-07-24
IRB Approval Number
2025/ET000577
Analysis Plan