We assessed problem and appropriate behavior in the natural environment from a matching perspective. Problem and appropriate behavior were conceptualized as concurrently available responses, the occurrence of which was thought to be determined by the relative rates or durations of reinforcement. We also assessed whether response allocation could be accounted for by relative rates or durations of an event not shown to reinforce problem behavior. The effects of the temporal proximity between a response and stimulus and the unit of repeated observations were examined. Results highlighted potentially important reinforcement parameters (e.g., duration) and the time frame in which reinforcement effects might be expected to occur. Although findings are reported for only 1 participant, the purpose of the current study was to assess methodological features of characterizing response-reinforcer relations in the natural environment. (Contains 4 figures, 1 table and 2 footnotes.)