The incorporation of reformed, inquiry-based pedagogies in introductory courses has been shown to improve content knowledge, student retention, interest and attitudes towards science. However, there is evidence that suggests these techniques are not being widely used by the geoscience community. This research focuses on the incorporation of inquiry-based activities in introductory Physical Geology labs and the relationship between classroom practices and teaching beliefs of geoscience instructors to better understand and address the gap between the literature and practice. Three mixed-methods studies are described here that include classroom observations, semi-structured interviews, and assessment of classroom materials (labs). Participants include faculty members from across the country who have completed workshops through On the Cutting Edge and Graduate Teaching Assistants (GTAs) from a large, public research university in the southeast. Providing higher inquiry labs is one way to promote reformed teaching in introductory courses. An introductory Physical Geology lab course had been designed around inquiry labs requiring student-centered pedagogy. Chapter 2 describes our efforts to assess how much inquiry is present in each lab and determine how GTAs approached teaching these activities. We use the Reformed Teaching Observation Protocol (RTOP; Sawada et al., 2002) to describe the degree of reformed instruction in a lab class using these higher inquiry Physical Geology labs. GTAs were able to teach the labs in a consistent manner, despite having minimal instructional training. There was a moderate relationship between the RTOP score and degree to which students' grades are accounted for at higher or lower levels of inquiry. There are a wide variety of modifiers and terms associated with inquiry that complicate efforts by instructors to identify or adopt inquiry-based activities in their own courses. In Chapter 3, we discuss several measurement protocols designed to describe to what extent inquiry is present, and select one (Buck et al., 2008) to assess the level of inquiry present in four Physical Geology laboratory manuals. One of the manuals was developed by and in use at a large, public, research university in the southeast. The majority of activities used in Physical Geology laboratory manuals are classified at low levels of inquiry that emphasize confirmation of information that is already known. This indicates that inquiry may not be one of the underlying frameworks used in their development. The university laboratory manual was developed with the goal of including more inquiry-based learning activities. It contained a significantly higher proportion of higher level inquiry activities compared to the other three lab manuals. This demonstrates that it is possible, if atypical, to incorporate higher level inquiry activities in introductory Physical Geology labs. We discuss how other instructors or lab developers can incorporate higher levels of inquiry in their labs, matching them with the type of information or skill they want students to learn. Adoption of reformed, inquiry-based materials is at the discretion of the instructor. An evaluation of the relationship between classroom practices and teaching beliefs is therefore critical in understanding why the implementation of reformed pedagogies in the geosciences is not more widespread. Chapter 4 explores this relationship using the RTOP and Teacher Beliefs Interview (TBI; Luft and Roehrig, 2007). We identified a strong, positive correlation between teaching practices and teaching beliefs. This indicates that both constructs are important to consider in creating professional development opportunities that encourage the implementation of reformed teaching practices. We end by discussing the role of personal practical theories and professional development in changing both practices and beliefs, and models that describe these changes. [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.]