DESCRIPTION (provided by investigator): Patients diagnosed with early-stage prostate cancer not only have to adjust to the psychosocial and physical consequences of their disease, but also must make sense of often complex and probabilistic information about their condition and treatment options. Yet, surprisingly, there are few structured and effective programs available to inform patients about their treatment options and to assist them in their treatment decision. We propose to develop and evaluate a computer-based multimedia intelligent expert system, designed to inform patients diagnosed with early stage prostate cancer about the disease, their treatment options, and about potential treatment consequences. The Prostate Intelligent Expert System (PIES) will present disease and treatment information that is targeted to the patient?s ethnicity and age, and tailored to his information seeking preference. The development of the program is guided by a cognitive-social approach to health information processing, which postulates that cognitive factors (i.e., expectations and beliefs about the disease and its treatment) and affective factors (i.e., cancer related worry) influence information processing and decision-making. From a technical point of view PIES is based on a successful multimedia intelligent expert instructional program to teach undergraduate courses in electrical engineering. The expert system goes beyond the common "if. then" statements used to tailor information to patients. Rather it continuously monitors the patient?s interaction with PIES, and thus is able to tailor information closely to the patients needs. PIES simulates a virtual health center. The patient can explore different virtual rooms (e.g., the library, the physician?s office, a support group, etc) to obtain information in an interactive way. Information will be presented through text, video, audio, and animation. The intelligent expert system will adjust the level of complexity of the information to meet the patient?s observed and stated information seeking preference. The feasibility and usability of PIES will be evaluated throughout the development period by the consulting physicians and by members of the target audience through focus groups and individual sessions during which patients explore earlier versions of the program. Formal usability and feasibility testing will be performed with early-stage prostate cancer patients (N=90) using a within-subject design. Assessments about prostate cancer knowledge and distress about treatment decision making will be obtained prior to and after completing PIES. Six weeks later patients? (N=81) treatment choice will be assessed. It is expected that PIES will result in an increase in disease and treatment knowledge, high satisfaction ratings with the information provided, and that PIES will facilitate treatment decision making.