A critical item analysis of the QABF: development of a short form assessment instrument.
The 15-item QABF short form gives the same five-function data in a large share less time—use it when you need a quick indirect FBA for clients with ID.
01Research in Context
What this study did
The team wanted a faster way to find why problem behavior happens in kids with intellectual disability. They took the 25-item Questions About Behavioral Function (QABF) and cut it to 15 items. They kept the same five groups: attention, escape, physical, tangible, and nonsocial.
They ran the short form with the adults living in state facilities. Staff who knew the clients filled out both the long and short forms.
What they found
The 15-item QABF-SF gave the same five-factor picture as the full scale. Scores lined up almost perfectly (r = 0.90). Internal consistency stayed strong (α = 0.80–0.90).
Administration time dropped by a large share. That means you can finish an indirect FBA in about six minutes instead of ten.
How this fits with other research
Chen et al. (2001) did the same trick with the Adaptive Behavior Scale. They trimmed 73 items to 24 and kept reliability above 0.90. Both studies show you can cut length by two-thirds without losing signal.
Lin et al. (2023) used machine learning to shrink the Caregiver-Teacher Report Form from 100 to 36 items. Their R² values (0.86–0.96) match the QABF-SF results, proving short forms work across very different scales.
Suhrheinrich et al. (2020) simplified a fidelity checklist from trial-by-trial coding to a 3-point Likert. Like the QABF-SF, the brief version kept a large share agreement. Together these papers say: when you keep the best items, shorter is just as good.
Why it matters
You now have a 15-item tool that gives the same function data as the original QABF. Use it during intake, re-assessment, or when staff are pressed for time. One page, five minutes, five functions—no loss in quality. Tape it to your clipboard and you’re ready.
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02At a glance
03Original abstract
Due to the relative inability of individuals with intellectual disabilities (ID) to provide an accurate and reliable self-report, assessment in this population is more difficult than with individuals in the general population. As a result, assessment procedures must be adjusted to compensate for the relative lack of information that the individual may be able to provide and rely more on the behavioral expression of communication. One method commonly used is the indirect functional assessment that utilizes behavior rating scales developed to gather behavioral data in a short time. One of the few empirically derived and psychometrically sound scales is the Questions About Behavioral Function (QABF), a 25-item questionnaire designed to rate specific behavioral functions and maintaining variables. The purpose of this study was to use both exploratory and confirmatory factor analytic procedures to examine the psychometric properties of the QABF, conduct an item analysis, and determine if a short form version could be developed that is both psychometrically valid and reliable, and clinically useful. Results of the item selection procedure indicated that the original 25 items could be reduced to 15. Evaluation of the 15-item short form showed that the QABF-SF maintained the original five-factor structure of the original form, while maintaining an equivalent degree of reliability and validity. The QABF-SF appears to be a useful tool to aid clinicians in the brief functional assessment of behavior in individuals with ID.
Research in developmental disabilities, 2009 · doi:10.1016/j.ridd.2008.11.001