There is an assumption that pedagogical content knowledge (PCK) is observable and measurable. Yet, in many studies referencing PCK, the construct of PCK remains both undefined operationally and poorly described. In physical education, although one study has measured teachers' PCK using teachers' weak and strong units of instruction (Ayvazo, 2007), there are no studies that directly examine the relationship among content knowledge (CK), PCK, and student learning. The purpose of this study was: (a) to examine the effects of a CK workshop on the improvement of teachers' PCK, and (b) to examine the effects of changes in teachers' PCK on student learning in a middle school soccer unit. A descriptive design was used to investigate teachers' teaching behaviors using a behavior analytic theoretical framework. Two middle school physical education teachers' soccer units were examined using direct observation in the comparison and the experimental groups. The following variables were measured: task maturity and appropriateness, verbal (e.g., instructions, descriptions, analogies and metaphors, cues, and specific congruent feedback) and visual (e.g., demonstrations, gestures, task cards, pictures, and diagrams, video clips, and physical assistance) representations, task adaptations for teachers, together with three student variables, correct, incorrect, and off task performance. Results showed differences between the comparison group and the experimental group in all variables. These differences demonstrated that teachers showed more mature PCK following the CK workshop than before the workshop. Conceptually, the findings in this study provide a validation for the variables of task maturity and appropriateness. The findings also (a) validate the assumption that PCK is exists on a continuum from immature to mature and (b) provide descriptive evidence that improving CK can improve PCK. Methodologically, a momentary-time sampling strategy was used to assess student performance and this strategy has not been used in physical education. This strategy was accurate in recording student performance. The use of new variables such as task maturity and appropriateness provides a new set of variables to examine PCK. [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.]