Measurement invariance of a Posttraumatic Stress Disorder symptoms measure (PCL-5) in college student and Amazon’s mechanical TURK samples.

Abstract

Objective: College student and Amazon's Mechanical TURK (MTURK) samples are regularly utilized in trauma research. Recent literature, however, has criticized these samples for not being generalizable to the general U.S. population. The purpose of this study was to determine whether college student (n = 255) and MTURK (n = 316) samples are invariant on the Posttraumatic Stress Disorder Checklist for DSM-5. Method: Measurement invariance using confirmatory factor analyses was used to determine whether groups are invariant across factor structure, factor loadings, item intercepts, and residual error variances on a given measure of Post-traumatic Stress Disorder (PTSD) symptom severity. Results: Model fit indices indicated the sevenfactor Hybrid model was the best-fitting model, but the six-factor Anhedonia model was the most parsimonious model. Both models demonstrated equivalence in factor at the strictest level, indicating MTURK and college student samples are similar in regard to PTSD symptom severity. Conclusions: These findings provide evidence that these groups can be combined in future studies to increase sample size for trauma research. Only the Anhedonia factor exhibited mean differences between groups, which may be related to true differences between college students and MTURK survey-takers. This study provides further evidence that the findings from trauma studies using these populations are generalizable to each other. Clinical Impact StatementAmazon's Mechanical TURK (MTURK) participants have emerged as an alternate solution to college students for collecting samples in psychology research. While MTURK participants are believed to be more representative to the general population than college students, there are concerns pertaining to generalizability across both groups. This study conducts measurement invariance testing on one measure of Post-traumatic Stress Disorder to determine whether MTURK participants and college students are invariant. Findings from this research show that findings from trauma studies using these populations can be generalized to each other.