Occupational therapy education standards have recently changed to require students to demonstrate knowledge and use of the safe and effective application of physical agents. This change, which occurred in 2020, is more rigorous in the area of deep thermal and electrotherapeutic agents than in previous revisions. This mixed-methods convergent study surveyed occupational therapists who are also Certified Hand Therapists to learn how they developed competence in the use of electrotherapeutic and deep thermal physical agents and what they believed to be effective educational methods in their learning. A survey gathered quantitative data for the study. Follow up semi-structured interviews were completed to gather qualitative data. Data analysis included descriptive statistics for quantitative data and demographic data, as well as inferential statistics through the use of single-factor analyses of variance with post hoc testing. Results indicated practitioners use a variety of training methods to develop competence in the use of complex physical agents. Continuing education and fieldwork education resulted in higher levels of independence when compared with manufacturer's sales representative training. Continuing education, fieldwork education, entry-level education, post-professional education, on-the-job training were associated with higher levels of competence than no training at all, indicating the aforementioned methods were all effective in developing competence. Triangulated results support learner demonstration, supervised and repetitive practice, and feedback during learning as essential methods for developing competence in complex physical agents. This study provides recommendations for effective educational methods for teaching and learning complex physical agents applicable to occupational therapy educators, novice practitioners, and occupational therapy students. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]