Background and Purpose. Critical thinking, knowledge, skill, and self-reflection are the hallmarks of clinical reasoning in physical therapy. Teaching and measuring a highly complex entity such as clinical reasoning is a challenging task and often requires multiple pedagogies and assessments. Knowledge and skill are frequently assessed by educators, but critical thinking and skills of reflection are not. Previous studies have used standardized tests to assess clinical reasoning skills of physical therapist students. These studies report conflicting findings potentially due to the fact that neither test was designed to test critical thinking of allied health practitioners. The Health Sciences Reasoning Test (HSRT) was designed specifically for health science students with questions written in a health care context.Participants. In 2008, 63 students, 37 from a public East Coast university and 26 from a private Midwest university were recruited to complete the HSRT.Method. The students completed the HSRT at 3 points in their education: upon entry to the program, prior to final affiliations, and again just prior to graduation.Outcomes. Analysis indicated a statistically significant change for the total score as well as the deductive and analysis subscales. Post-hoc analysis indicated these differences occurred between times 1 and 2 for the total score as well as both subscales. There was a significant difference between the 2 schools after adjusting for variance in initial test scores. The Midwest school's mean score (24.85) was greater than the east coast school's (22.42), and this difference was significant F^sub l^ = 12.65; P Conclusion. The HSRT was able to detect change in critical thinking scores. This finding, coupled with those of a previous study in which the HSRT was able to detect differences between experts and novices, indicate the HSRT may have validity and therefore may be a useful tool for assessing the critical thinking skills of physical therapist students.Key Words: Assessment, Clinical reasoning, Critical thinking.INTRODUCTIONThe Commission on Accreditation of Physical Therapy Education (CAPTE) requires physical therapist education programs to develop and assess students' clinical reasoning skills.1 While clinical reasoning skills have always been an important component of physical therapist education, this mandate, coupled with direct access and the move to a doctoring profession, increases the importance of teaching and assessing clinical reasoning skills of physical therapist students.Clinical reasoning refers to the thinking and decision-making process used during examination and management of patients.2 It is a complex mechanism that requires basic scientific knowledge, clinical competence, the ability to self-reflect, and critical thinking skills. Critical thinking is the disciplined, intellectual process of applying skillful reasoning as a guide to belief or action and involves the cognitive abilities of analysis, interpretation, inference, evaluation, and explanation.3 The relationship between critical thinking and clinical reasoning is poorly understood and the terms are often interchanged. Clinical reasoning can be conceptualized as critical thinking within a specific domain or a particular point of view of a field, in this case the field of physical therapy. Physical therapists apply the components of critical thinking about and within the field of physical therapy, which has a certain point of view. This point of view is based on the objects, events, and investigations we consider in our area of expertise.4 The result of this critical thinking within our domain of practice and within the point of view of the field can be considered clinical reasoning. If one accepts this postulate then the skills required for critical thinking (ie, analysis, interpretation, inference, evaluation, and explanation) would be considered inherent in the clinical reasoning process but would be used contextually within the domain of physical therapy. …