The key to better education practices and desired educational outcomes is to have a motivated and superior teaching work force. Many educational policies of the past 20 years, including teacher proof curriculum, test-based instructional management, and student competency testing, were based on the assumption that education could be improved without improving the quality of teachers . To have an effective teaching cadre not only is it necessary to recruit competent teachers who are required to meet high educational standards and who demonstrate an aptitude for teaching, but it is also necessary to continually engage the teachers in the process of learning to become more effective teachers. Although much research is available on staff-development models, few studies have examined the issue of professional development from the teachers' perspective.
The focus of this study was to understand why some teachers evaluated as marginal or incompetent were able to effect sufficient change in their teaching behaviors to be recognized later as competent or even excellent teachers. The evaluation procedure is traditionally the avenue through which the principal assesses teacher competence. An outcome of the evaluation process should be to encourage the marginal teacher to improve and develop better classroom skills. Instead, some marginal teachers are tolerated or ignored as long as they are not the target of persistent or massive parental complaints. This study presents qualitative research on selected high school teachers who were identified as marginal or incompetent in their professional evaluation but later demonstrated remarkable improvement in their teaching performance. The inquiry took a heuristic and inductive approach to broaden the knowledge of the phenomenon of positive change in teaching behavior. It also examined the role of school-level assistance efforts in professional development from the teachers' perspective.
Research has shown that there are consistent differences in teaching behaviors of effective and less-effective teachers (