The reliability and validity of the QABF have been well established in applied settings.
Test--retest, inter-rater, and internal consistency reliability of the QABF have also been evaluated in applied settings (Freeman, Walker, & Kauffman, 2007; Nicholson et al., 2006; Paclawskyj et al., 2000; Singh et al., 2006).
Despite the evidence supporting the psychometric properties of the QABF institutional settings with persons with intellectual disabilities, there is some concern as to whether tools such as the QABF are applicable to students in school settings with diverse disabilities (Quinn et al., 2001).
The clinical utility of indirect behavioral assessments like the QABF relies not only on the assessor's ability to obtain all necessary data, but also on the ability of raters in a particular setting to agree on environmental variables maintaining problem behavior (e.g., Pence et al., 2009).
The QABF is a 25-item questionnaire designed to identify the functions of problem behavior.
If one functional subscale on the QABF received a greater total score than the others it was labeled as the primary function.
Internal consistency for ranking each functional category on the QABF was assessed by obtaining alpha coefficients for all respondents combined, and for teachers and paraprofessionals separately (Cron-bach, 1951; Guttman, 1945).
Table 2 Interrater Reliability for the 25 QABF Items Median item Average Median Kendall's Average ICC Pearson Spearman tau-b Kappa 1.
Table 3 displays item-total correlations, including the means (ranging from 0A3 to 1.90), standard deviations (ranging from 0.74 to 1.15) and the correlation between each item on the QABF with its corresponding functional category scores.
Table 5 Means, Standard Deviations, and Internal Consistency of QABF Functional Categories Internal Consistency Reliability (alpha) Functional Mean Standard Overall Teacher Paraprofessional Category Deviation (n =134) (n = 45) (n = 89) Attention 6.90 3.43 0.67 0.64 0.68 Escape 7.07 2.64 0.36 0.12 0.42 Nonsocial 4.87 3.05 0.51 0.27 0.57 Physical 2.79 3.10 0.77 0.38 0.80 Tangible 5.28 3.26 0.59 0.53 0.60 CFA results are summarized in Table 6, where the originally proposed five-factor model (Model 1) provided an inadequate description of the data using the aforementioned criteria.