Despite the fact that evolutionary theory is the central and unifying theme in biology, it has not been well received by the general public in the United States. Several studies reveal that many Americans have a poor understanding of evolution and reject it as a valid explanation of the current state of life (Gallup, 1993; National Science Board, 2000; Recer, 1996). In response to this, there has been a significant effort by the science education community to improve the effectiveness of evolutionary biology education. A primary focus of this endeavor has concerned the development of curricula and instructional strategies that foster student learning of evolutionary biology. Many of these efforts emphasize the lines of evidence supporting evolutionary theory and the theory's scientific validity in light of science as a method of inquiry (Farber, 2003; Cherif, Adams & Loehr, 2001; Alles, 2001; Nickels, Nelson & Beard, 1996; McComas, 1994; National Academy of Science, 1998; Scharmann, 1993). These strategies may be particularly effective because they equip students to make informed decisions about the scientific validity of evolution by focusing on the evaluation of evidence within the framework of the discipline, rather than presenting information as facts that must be memorized or by focusing on religious belief (Clough, 1994). Determining the effectiveness of these novel instructional strategies remains an important challenge of evolutionary biology education.
One method of measuring the effectiveness of instruction in evolutionary biology is by assessing changes in student acceptance of, rather than belief in, evolutionary theory as a scientifically valid and explanatory theory. This strategy is consistent with conceptions of science as a method of inquiry that stress empirical adequacy and explanatory power over belief (van Frassen, 1980), and has been advocated as an effective method for effectively teaching evolution (Clough, 1994; Scharmann, 2005). Schwabb (1978) framed the issue by observing that a discipline consists of substantive and syntactical structures, both of which must be considered in assessing a theory. The substantive structure of a discipline consists of theories, concepts, and facts (the substance of the discipline) while the syntactic structure consists of the process by which knowledge is warranted or its validity is determined (the discipline's methodology). Thus, informed decisions of acceptance of scientific theories are appropriately made as a result of the critical analysis of available data in light of the established methods of the scientific discipline.
Instrumentation has been developed to assess acceptance of evolutionary theory. Rutledge and Warden (1999) developed and established the reliability and validity of the Measure of Acceptance of the Theory of Evolution (MATE), a 20-item Likert-scale instrument designed to assess high school biology teachers' overall acceptance of evolution (Appendix A). As informed decisions of acceptance or rejection of a scientific theory are based on evaluations of substantive and syntactical elements of a domain, fundamental concepts of evolution and of the nature of science as a method of inquiry are the focus of MATE items (Table 1). The MATE has been utilized to assess high school biology teachers' acceptance of evolution in Indiana (Rutledge & Warden, 2000) and Oregon (Trani, 2004), and is currently being utilized at the University of Waikato in a study of New Zealand secondary teachers (http://sci.waikato. ac.nz/evolution/aboutus.shtml). Alters and Nelson (2002), in their review of effective pedagogy of evolution in higher education, noted the potential of the MATE with respect to research in evolutionary biology education. However, the reliability of the MATE in a test-retest scenario-needed to assess the effectiveness of instruction in evolutionary biology--has yet to be evaluated.
The "reliability" of an instrument is a measure of its consistency. …