<p>Focus of Thesis This thesis focuses on the initial stages of developing the Ontario Decision Aid in Rectal Cancer for Stage II and III patients (ODARC). The ODARC is a DA meant to facilitate relevant information exchange among physicians and patients. Such a tool should enhance patient knowledge and accuracy of treatment expectations by effectively conveying to patients relevant information on treatment options and associated benefits and risks. The ODARC is designed for use during a physician-patient consultation. The ODARC prototype development was guided by a workbook on developing & evaluating patient DAs published by O’Connor & Jacobsen (for efficiency we will call this the Workbook).24 This latter document provides detailed instructions for a 7-step DA development process including: 1) assess patient and provider need 2) assess DA feasibility 3) define objectives of the DA 4) identify the framework to guide DA development 5) select tailored methods of decision support to be used in the DA 6) select the designs and measures to evaluate the aid and, 7) plan dissemination.24 In this thesis we have created a prototype ODARC as informed by Steps 1 to 5 of the Workbook. The last two steps covering evaluation and dissemination are beyond the scope and available resources of this current research effort, and can be considered as future research endeavours. This will be reviewed in the final chapter.</p> / Master of Science (MSc)