This dissertation in practice explores common themes between teachers' perspectives of effective professional development experiences and the perceived impact of professional development on classroom teaching practices. The following questions guided the study: 1. What are teachers' perceptions of completed professional development activities in terms of effectiveness in improving self-efficacy that enhances teachers' productivity in the teaching-learning process? 2. What are teachers' perceptions of professional development activities in terms of the improvement of student involvement in the teaching-learning process that leads to active learning? 3. What are teachers' perceptions of professional development activities in terms of the improvement of content delivery that ensures that learners understand and master the topics discussed? 4. What are teachers' perceptions of professional development activities in terms of the improvement of self-esteem that influence teacher self-concept for enhanced performance? 5. What is the one professional development activity that would help teachers improve student achievement the most? This study employed a phenomenological research methodology as it allowed for the exploration of how teachers and administrators, at the secondary level of education, perceive professional development opportunities that are being offered. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]