Individuals with a cancer-predisposing genetic trait have a lifetime risk to develop cancer approaching 100 percent, and cancer often strikes early in age, before standard recommended cancer screening begins. Identifying hereditary cancer predisposition through genetic cancer risk assessment (GCRA) allows for intensified measures to prevent cancers or detect them at an earlier, more treatable stage. There is a surge in demand for GCRA services across the nation, but few clinicians with adequate training to provide GCRA services. The City of Hope Cancer Center conducts a multimodal GCRA training course for physicians (MDs), advanced practice nurses (APNs) and genetic counselors (GCs), delivered through nine weeks of distance didactics and five days of face-to-face case-based workshops, followed by 12 months of prescribed Web-based professional development activities. As currently designed, the course cannot meet increasing demands for cancer genetics training. This study employed a quasi-experimental design with a nested process component to compare knowledge, case-based skills and professional self-efficacy outcomes of clinicians who engaged in case-based training concurrently with distance-mediated didactic learning through Web-based case conferencing (intervention group) with outcomes of clinicians who participated in the established course design, with case-based learning conducted through face-to-face workshops (comparison group). The process component employed survey and roundtable discussion group methods to gain insights about the Web conference learning experience from the perspectives of the intervention group participants. A preliminary cost analysis was also conducted to compare the expense of face-to-face workshops with those of Web-based case conferences. Ninety-six clinicians participated in the study. The comparison group (n = 44) and the intervention group (n = 52) were each comprised of two cohorts who participated in the course in the years 2009 and 2010, respectively. The majority of participants in both groups were female (86 and 89 percent, respectively), Caucasian (82 and 73 percent, respectively) and had some GCRA practice experience (84 and 94 percent, respectively). No statistically significant differences were found between cohorts or groups in composition of practice discipline (MDs, APNs and GCs), practice setting, years in clinical practice, previous GCRA experience, or in baseline knowledge, case-based skills or professional self-efficacy scores. Results of comparative analysis revealed statistically significant pre-to-post increases in both comparison and intervention groups on knowledge, case-based skills and professional self-efficacy scores (p less than 0.000 for each variable). Pre-to-post between-group comparisons were statistically significant on percent change in knowledge (p less than 0.015) and in post-knowledge score (p less than 0.000). Pre-to-post changes in case-based skills and professional self-efficacy scores were comparable between groups, with no statistically significant differences (p less than 0.33 and p less than 0.30, respectively). Results support (and in knowledge outcomes, exceed) the hypothesis that intervention group outcomes would be equivalent to comparison group outcomes on established course pre-post assessments. Findings from the process analysis revealed that the Working Group learning experience generated new learning and reinforced existing knowledge in a broad spectrum of GCRA-related knowledge and skills domains. Engagement in Working Group helped participants identify, reflect upon and articulate individual knowledge and skills deficits. These findings, combined with feedback on limitations, connectedness and communication during Working Group participation, will inform the development of a practical, more accessible new course design that incorporates Working Group Web conferencing as a key source of distance-mediated case-based training aligned with the highest standards of accountability in continuing medical education (CME). Further research to examine the effectiveness of this and other Web-based case conference and tumor hoard environments will enhance the learning potential of CME-accredited distance-mediated case conferencing, and will contribute to the body of theoretically- grounded approaches to continuing medical education and professional development. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]