With more and more focus on accountability, algebra achievement has become a major focus of math curriculum developers. In many states, students are expected to pass standardized Algebra achievement tests in order to satisfy graduation requirements. The purpose of this study was to identify teacher qualities and teaching qualities linked to teacher effectiveness in 7th-grade Algebra I Honors. This study examined two aspects of teachers, teacher quality and teaching quality. Teacher quality refers to the characteristics that teachers possess and teaching quality refers to what teachers do in the classroom to foster student learning. For this study, teacher quality included teacher professional preparation characteristics and teacher knowledge. Also, aspects of teaching quality that promote conceptual understanding in Algebra were examined. In this mixed methods study, quantitative data were used to determine a relationship between teacher qualifications and student achievement. Qualitative data were used to gain an in-depth understanding of the characteristics of teaching quality. Based on the findings of this study, in this group of teachers, there is a relationship between teacher quality and teaching effectiveness; however it is very limited and only based on participation in two specific workshops. The difference between more and less effective teachers in this study lies in teaching quality, what teachers do in the classroom, as opposed to teacher quality, what those teachers bring with them to the classroom. The findings of this study indicate that elements of teaching quality are more indicative of teacher effectiveness than elements of teacher quality among teachers in the study. Although there was some evidence of a relationship between elements of teacher quality and teacher effectiveness, there were clear differences in teaching quality among more effective and less effective teachers in this study. [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/en-US/products/dissertations/individuals.shtml.]