Danielson and McGreal (2000) stated two primary purposes of teacher evaluation: quality assurance and professional development. The former is achieved through summative evaluation while the latter is achieved through formative evaluation. Summative evaluation aims to license, hire, give tenure to, promote, demote, or dismiss teachers. On the other hand, formative evaluation aims to encourage the professional growth and development of its teachers, shape performances by giving appropriate feedback, build new practices or alter existing practices (Peterson, 2000).
Although both types of evaluation aim to measure teacher performance, the formative evaluation identifies ways to improve performance and the summative evaluation determines whether the performance has improved sufficiently such that the teacher can be rewarded. While each type is valuable, neither type can lead to reform on its own. When coupled, however, formative and summative evaluations provide optimal professional development opportunities (see Nolan & Hoover, 2005) and tenure (Brandt, Mathers, Oliva, Brown-Sims, & Hess, 2007).
Despite their complementary nature, some teacher evaluation systems focus on summative evaluation at the cost of formative evaluation. They use summative evaluation to build a case to dismiss incompetent teachers. This approach has several drawbacks: (a) it is not conducive to fostering an honest, open, and pedagogically sophisticated dialogue between principals and teachers; (b) it raises the level of tension and anxiety and makes it more difficult to admit errors, listen, and talk openly about areas that need improvement; (c) it doesn't prod teachers to emerge from their isolation and reflect with their colleagues on what they need to change in order for more students to succeed; (d) it doesn't give clear direction on the ways in which teachers can improve their performance; and finally it does not motivate a mediocre teacher to improve--or spur a good teacher on to excellence (Danielson & McGreal, 2000).
Crew, Everitt, and Nunez (1984) found two major philosophical problems with judgmental evaluation. First, it focuses on poor teacher performance and gathers documentation on a teacher's weaknesses. Second, it does not candidly address weaknesses observed in teachers. Evaluation will be more conducive to thought and reform if it focuses on the positive side of teacher action.
Evaluation will be exempt from the foregoing pitfalls if it systematically links teacher evaluation and staff development (Marshall, 2005). Marshall believes that evaluation facilitates teacher growth if it is based on multiple sources of data, includes clear, relevant, and meaningful performance criteria, focuses on peer assistance and teacher goal setting, and fosters mutual trust between the teacher and evaluator.
Evaluation can be limiting if it is judgmental. It can be limited if it is based on a single source of data. For instance, in some universities such as Iranian universities, evaluation is mainly based on students' views. To provide a better picture of teaching performance, students' views should be juxtaposed to the review of teachers' lesson plans (Stronge, 2007), classroom observations (Mujis, 2006), self-assessments (Uhlenbeck, Verloop, & Beijaard, 2002), portfolio assessments (Brandt et al., 2007), student achievement data in standardized tests (Brandt et al.), and student work-sample reviews (Mujis). Though useful as a source of information, each of the foregoing methods of teacher evaluation has its own limitations.
1. Review of lesson plans: planning is a window to teacher preparation and correlates with student learning (Stronge, 2007), but lesson plans are adjusted during their implementation. Thus, assessment of plans cannot account for the quality and appropriateness of adjustments.
2. Classroom observations: observation captures information about what actually occurs in the classroom (Mujis, 2006), but poorly trained observers and brief observations are usually biased (Shanon, 1991). …