The purpose of this quantitative correlational study was to investigate relationships between grade levels, personal factors of teachers, and instructional variety used by 4th-12th grade teachers in Kern County, California. The population under investigation included 2,844 teachers. 235 elementary, middle school/junior high, and secondary teachers responded to the survey who teach core areas at 12 participating school districts to answer three research questions. Data analysis occurred in three phases (exploration of the data, hypotheses testing, and analysis of relationships) and consisted of descriptive statistics, one-way ANOVA tests, Pearson and Spearman correlations, and multiple regression. The results supported the rejection of H1[subscript O], H2[subscript O], and H3[subscript O]. The rejection of the null hypotheses provided support for the alternative hypotheses. Relationships between the independent and dependent variables established a link between grade levels, the educational and professional backgrounds of teachers, and instructional variety. Educational leaders should examine background factors to improve instructional variety. Teachers may improve instruction through professional development programs containing components of the Formative Assessment of California Teachers (FACT), shown to relate to increased instructional variety in English/language arts, science, and mathematics. Chapter 5 contains a comparison of the study to the literature and additional conclusions and recommendations. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]