In this dissertation I explore characteristics which influence the implementation of evidence-based instructional practices of six post-secondary chemistry instructors in Colorado who report current use of these practices. The purpose of this study was to identify these characteristics to recognize areas of focus for future professional development. Knowledge and beliefs were also explored, as characteristics are often a culmination of these individual beliefs. Using a qualitative case study approach, a survey, classroom observations, and semi-structured interviews were used to collect the data for this exploration. Instructors were observed using the Classroom Observation Protocol for Undergraduate Science, Technology, Engineering and Math (STEM) classes to identify if these beliefs aligned with their classroom practices. In this study I identified four main characteristics from patterns in these data using reflexive thematic analysis (TA) which revealed that instructors who do implement these practices have: intellectual humility, an equity mindset, a commitment to learning, and social awareness. Beliefs identified included: beliefs about instructor role, how learning happens, and the value and limitations to implementing evidenced-based instructional practices. These beliefs were found to be aligned with the transitional and student-centered practices of participants in this study. These results suggest a need to explore larger concepts such as intellectual humility, rather than the individual knowledge and beliefs which contribute to these larger concepts. This approach would allow researchers to encapsulate varied experiences that all ultimately lead to the implantation of evidence-based instructional practices and to make suggestions for future teacher training and professional development opportunities. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]