We conducted functional analyses and identified reinforcers for problem behavior for three individuals with developmental disabilities. Based on results of the functional analysis, we evaluated the rate, probability, delay, and duration of reinforcement for problem and appropriate behavior during descriptive parent-child observations. Results showed that parameters of reinforcement, including rate, probability, delay, and duration may interact, and that evaluations of a single reinforcement parameter may be insufficient in describing response allocation. Hence, this study represents a movement toward a method for analyzing reinforcer dimensions, other than rate and probability, in a descriptive analysis.