This paper reports on evaluating the validity and reliability of the recommendations made by the computer program.

We conducted formative evaluations using think-aloud techniques to make the program clear and user friendly.

To validate the accuracy of clients' physical self-assessments, a Physical Therapist did a hands-on assessment of four older clients, and compared her assessment with the clients' self-assessment.

To validate the accuracy of the computer program's exercise recommendations, the self-assessments of 40 clients were submitted to three expert Physical Therapists. Each PT recommended exercises based on those assessments. The PT's recommended exercises were compared to each other and were compared to the program's recommended exercises.

To assess the reliability of the clients' assessments over time, 23 clients took the PEP program on day 1 and on day 8.

Using Cochran's coefficients, pairwise kappas, and McNemar's chi squares, we concluded that PEP can select a personalized exercise regimen from 30 exercises similar to those a professional physical therapist would select from the same group.