With the increasing demand for accountability of Extension programming, Extension professionals need to apply rigorous evaluation designs. Randomized designs are useful to eliminate selection biases of program participants and to improve the accuracy of evaluation. However, randomized control designs are not practical to apply in Extension program evaluation. This article explains how to use the crossover design as a practical tool for evaluating Extension programs rigorously. This design can be used to evaluate any Extension program with two or more curricula presented to client groups in multiple counties.