Two decades after the report "A Nation at Risk" by National Commission on Excellence in Education (A Nation at Risk: The imperative of educational reform, 1983), education professionals are still struggling with the issue of improving academic achievement as measured by standardized test scores. To reinforce the sense of national urgency about this issue, The Teaching Commission (2004) published a new report, "Teaching at Risk", stating that teaching quality is a critical factor in attempts to improve our national's global competitiveness, security and future. Whether there is any association between teaching quality and the nation's ability to compete in a global economy is an empirical question mat should be addressed in a the context of carefully defining teacher quality.
Purpose of this article is to examine the issue of the relationship between teacher effectiveness and students' achievement as measured by test scores. A strong belief among policy makers and public as well as private funding agencies is that test scores are directly related to the quality of teaching effectiveness (Kupermintz, 2002). This relationship implies that there could be a direct causality among teacher preparation, teacher quality, and student achievement. The terms "teaching effectiveness" and "teacher effect" are often used interchangeably in these conversations. In the following sections, we will discuss several aspects of each construct. Particularly, we discuss the following issues: (i) teacher effects, (2) teaching or teacher effectiveness, and (3) an educational model of school and teacher effects on student achievement. Fundamental research issues and concerns as well as an alternative conceptual framework for studying the relationship of achievement and teaching will be highlighted.
Comparing Teacher Effects and Teacher Effectiveness
In recent years, research on effectiveness of teaching has reported a direct relationship between its quality and student learning (Darling-Hammond & Young, 2002). Odden, Borman, and Fermanich (2004) indicated that teachers have a significant influence on student learning. However, the definition of teaching effectiveness is not clear and, in fact, is operationalized in terms of teacher effects, which are more easily quantified in research studies. Based on the literature discussion by Odden, Borman, and Fermanich (2004), the following teacher factors or effects are specifically identified. They were found to be, to different degrees, associated with student achievement and include: (1) years of teaching (Goldhaber & Brewer, 1997), (2) major of undergraduate study, particularly for mathematic and science teachers (Monk, 1994), (3) ACT or SAT test scores (e.g., Ferguson, 1998), (4) course work or degree obtained (Rowan, Chiang, & Miller, 1996), (5) quality of high school (Goldhaber & Brewer, 1997), (6) earning of a license (Darling-Hammond & Young, 2002), and (7) verbal ability (Ehrenberg & Brewer, 1995). Odden et al. (2004) suggest that these variables should be defined further, especially for the variables that show mixed effects.
Whereas these teacher effects can be defined relatively easily and studied, the teacher effectiveness is a very different matter. While the teacher effects can be operational zed as, for instance, the gender, experience and salary level of teachers, the operationalization of teacher or teaching effectiveness is not clearly articulated. For example, it is relatively a simple matter to study the relationship between teachers' salary and student achievement as a teacher effect since there is a large variation in teachers' salary. One could conclude, therefore, that students taught by higher paid teaches will be more successful on tests than pupils of lower paid teachers. However, such a teacher effect cannot be necessarily translated into teacher effectiveness; that is, a teacher's salary may not have anything to do with whether a teacher is effective in his/her teaching. …