The Aberrant Behaviour Checklist: a British replication and extension of its psychometric properties

. The Abberrant Behaviour Checklist was administered to 209 British mentally handicapped adults in two large residential facilities. This sample included a substantial proportion (45%) of non-ambulant people not included in previous studies. The five-factor solution originally reported by Aman et al. (1985a) was replicated using both four-point ratings and dichotomously recoded rating. For both methods of scoring, the five scales derived from Aman et al.'s original factor analysis remained highly internally consistent. Dichotomously coded ratings may offer the advantage over four-point ratings of retaining the same factor structure with better reliability.