The purpose of this study was to describe how male, collegiate, certified athletic trainers (AT's) represent knowledge during 5 injury evaluation scenarios. A second purpose of the study was to identify what self-regulatory behaviors participants engaged in to improve or maintain their skills. Knowledge representation was studied as cue selection and knowledge organization while completing the 5 evaluation scenarios during a situational interview. Demographic and self-regulatory behavior data were collected via a questionnaire. During the situational interview, participants responded to 5 injury scenarios via a think-aloud technique. Interviews were audio-recorded, transcribed, and member-checked for accuracy. Participants were expert AT's (n = 10) with jobs titles of Director of AT, Head AT, Assistant/Associate AT with a mean age of 41.9 plus or minus 9.78 years and 17.9 plus or minus 10.24 years of experience. The novice AT participants (n = 10) had titles of Graduate Assistant, Intern AT, and Assistant AT with a mean age of 24 plus or minus 1.94 years and 1.3 plus or minus 0.48 years of experience. Differences in groups included strengths with specific injuries and situations. Differences existed in the environmental focus, self-regulatory experiences and goals, and sources of feedback during the acquisition of evaluation domain knowledge. Significant differences (alpha = 0.05) in cue selection were present for only situation 2 (i.e. upper extremity injury) for critical cue selection F = (1,18) = 4.881, p = 0.04, and non-relevant cue selection F = (1,18) = 8.191, p = 0.01. Qualitative analysis of knowledge organization yielded expert and novice AT's both used production rules to guide their protocols. Additional analysis determined that expert and novice AT's both used causal and conditional relationships to link propositions in their protocols. Analysis of non-repetitions statements revealed experts represented knowledge contains fewer situation appraisal concepts, more history concepts, and more prediction concepts. The conclusions of this study may inform the study of expertise in healthcare and how experience in a domain may shape ones knowledge base. Subsequently these findings may contribute to interventions used to improve novice AT's evaluation domain knowledge. [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.]