Motivation to learn is an important component of education, particularly in the field of educational technology in which the instructor's physical presence is increasingly absent. The complexity of the many factors that contribute to student motivation renders this domain difficult to measure. The Instructional Materials Motivation Survey (IMMS) instrument was created to measure and identify issues related to student motivation within the use of self-directed learning materials. The IMMS was designed to measure the degree to which the learner becomes engaged in the learning experience through elements of attention, relevance, confidence, and satisfaction (ARCS). Since its creation, several academic studies have made use of the IMMS to assess student motivation, however these studies demonstrate a lack of consensus on the validity and reliability of the instrument. This study examined the validity and reliability of the IMMS as measured by baccalaureate nursing students who completed the IMMS survey instrument following a clinical training simulation. Validation of the survey data retained 19 IMMS items distributed across all four ARCS subscales. The findings reported extend previous validation evidence by validating the instrument with mixed reality instructional simulation. These findings demonstrate the agnostic nature of the IMMS instrument with regard to instructional delivery medium.