Proponents of specialized middle-grades teacher preparation believe that knowledge of early adolescent development is needed to teach young adolescents; however, preparation programs that focus on young adolescents are rare, particularly in California. Information addressing the extent to which California's middle-grades teachers are knowledgeable about early adolescent development is thus uncertain, as is the manner in which existing knowledge was gained.

The purposes of this study were to describe California middle-grades teachers' perceived and actual levels of knowledge of four areas of early adolescent development (i.e., physical, social, emotional, and cognitive), the manner in which that knowledge was acquired, and to what extent teachers believe such knowledge is essential for teaching students in the middle grades. Furthermore, this study examined differences in teachers' perceived and actual levels of knowledge based on years of experience teaching at the middle-school level, type of credential program completed, the amount of time spent observing or student teaching in a middle-grades classroom before becoming a middle-grades teacher, and the amount of previously completed coursework focused on early adolescent development.

Data were collected from a convenience sample of 143 California middle-grades teachers through their completion of a printed or electronic version of the California Middle-Grades Educator Questionnaire, developed for this study. Results indicated that participants primarily perceived their knowledge of early adolescent development to be proficient, teachers' actual knowledge tended to be midlevel to high, and many teachers believed their knowledge was acquired primarily through observation or experience in the classroom setting. Nearly all of the teachers believed an understanding of early adolescent development is essential or important to teaching the middle grades. No statistically significant differences were found to exist between teachers' perceived or actual levels of knowledge of early adolescent development based on the four independent variables. Recommendations were made for providing professional development for current middle-grades teachers to supplement knowledge gained through experience and additional learning opportunities for preservice teachers. Recommendations for future research included the implementation of a more extensive instrument, including teacher interviews, and the exploration of ways in which teachers' knowledge of early adolescent development is realized in the classroom setting.