Assessed the effects of frequency of prompting (phone calls once a week versus once every three weeks) and content of prompting (feedback and goal setting versus "touching base") in a walking program designed to meet ACSM's cardiovascular exercise goals. Survival analysis using six months of data points and using the criteria of walking at least 20 minutes a day for a at least three times per week indicated an effect for more frequent versus less frequent prompting (50% and 15%), but not for feedback and goal setting versus "touching base" prompting (31% and 30%). The results suggested the efficacy of frequent prompting delivered in inexpensive ways as a means to increase exercise adherence and the further parametric study of other basic behavior change strategies. / Ph. D.