On some psychometric properties of the questions about behavioral function (QABF) scale.
The QABF gives you a clear five-factor snapshot, yet two raters often disagree—always back it up with direct data before treatment.
01Research in Context
What this study did
Nicholson et al. (2006) checked how well the Questions About Behavioral Function scale works. They gave the QABF to staff who work with adults with intellectual disability. The team looked at three things: do the items hang together, do different staff agree, and does the five-factor model still fit.
What they found
The scale held up well inside one rater’s head. Internal consistency was high and the five factors stayed clear. But when two staff rated the same client, they only agreed modestly. Agreement dropped even lower for behaviors that happened rarely or looked painful.
How this fits with other research
Logan et al. (2000) built the QABF and first said it was psychometrically sound. Nicholson et al. (2006) add a caution flag: the tool is reliable on paper, yet people watching the same client still diverge.
Lew-Koralewicz et al. (2021) later repeated the check in Polish with kids on the spectrum. They found the same five factors and good numbers, showing the scale travels across languages and diagnoses.
Sheridan et al. (2023) flipped the lens and asked youth to rate themselves. Staff-youth pairs agreed about as well as staff-staff pairs, hinting that modest inter-rater agreement is simply part of the package, not a flaw of one group.
Why it matters
You can keep using the QABF as a quick screener, but treat low-rate or pain-topography scores as hypotheses, not facts. Pair the checklist with a short direct observation or a brief functional analysis before you write the behavior plan. One practical step: have two staff complete the QABF independently, circle any item they disagree on, and probe that function first in your next assessment session.
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02At a glance
03Original abstract
This study examined certain psychometric properties of the questions about behavioral function (QABF) scale. The QABF was completed on 118 problem behaviours presented by 40 young people with severe intellectual disabilities, and measures of inter-rater reliability, internal consistency, and construct validity were calculated overall and for subgroups of behaviours defined by topography and reported frequency. Levels of inter-rater reliability for both individual items and subscales were generally modest, but inter-rater reliability of rankings of subscale scores exceeded that reported for other comparable assessments. Inter-rater agreement was higher for higher rate behaviours and lower for maladaptive (versus disruptive and destructive) behaviours. Internal consistency was high for all QABF subscales, but also for the scale as a whole. Factor analysis yielded five factors clearly corresponding to the five QABF subscales and a sixth relating to a single item concerning the repetitive nature of the behaviour. Methodological issues which may have reduced levels of reliability are discussed. We conclude that in terms of psychometric properties, the QABF presents some specific advances on previous brief scales assessing behavioural function, but also that it continues to be appropriate to use other observational or experimental methods together with such scales when conducting functional assessments.
Research in developmental disabilities, 2006 · doi:10.1016/j.ridd.2005.04.001