Prior studies suggest that trial-based functional analyses (TBFA) can be used to identify the function of problem behaviors for individuals with intellectual and developmental disabilities. To date, there have been 16 published studies concerning TBFAs, however, across these studies there have been several variations in the procedures that appear to have been decided upon somewhat arbitrarily. ... [Show full abstract] For example, of the 16 studies, eight used a control segment after the test segment; five used a control segment prior to the test segment; one randomized the order of the test and control segments; and two studies used a control both before and after the test segment. Additionally, the number of trials conducted per test condition has varied between 3 and 20 trials. Despite the variation in the number of trials conducted, it appears as if researcher decided upon the number of trials to conduct prior to the TBFA, rather than using a stability criterion. The purpose of this study is to (a) examine patterns of responding in pre and post-control segments to determine if either or both are necessary and (b) evaluate response patterns within and across test conditions to determine if using stability criterion might be more appropriate to use when determining the number of trials to conduct. This study is also distinguished from prior studies in that primary caregivers will implement the TBFA in the homes of the children. Three children with developmental and intellectual disabilities participated in this study. At least one function was identified for two of the three participants. Of the two TBFAs in which a function was identified, both showed problem behavior occurring multiple times in the test and post-control segments; there was only one instance of problem behavior in the pre-control segments across all three participants.This suggests that there may have been carry-over effects occurring. For the two TBFAs in which a function was identified, a stable pattern of responding emerged prior to the termination of the TBFA, suggesting that a stability criterion could be a viable measure to use to decide when to terminate the TBFA. Finally, for both of the TBFAs in which a function was identified, a similar pattern of responding was found to occur when each segment was evaluated at 120-s and 60-s, suggesting that the segment could be conducted for only 60-s and capture the function of the problem behavior.