Experimental functional analyses for challenging behavior: A study of validity and reliability

The convergent validity of an experimental (analog) functional analysis was investigated by a comparison of three separate ways of interpreting the da ta derived from such an assessment: two previously published methods and th e criterion Z method derived by the authors. Data from the experimental fun ctional analysis of the challenging behavior(s) of 27 individuals with inte llectual disabilities were analyzed to assess agreement between the three f orms of interpretation. The rest-retest reliability of all three methods ov er periods of 2 weeks, 1 month, and 3 months was also calculated. The resul ts suggest that the methods of interpreting function from experimental asse ssments can give different results and that the test-retest reliability of the experimental functional analyses is poor. The implications of these fin dings are discussed in relation to clinical practice. (C) 1999 Elsevier Sci ence Ltd.