RESUMO
Introduction: The Mentoring Competency Assessment (MCA) is an example of a validated instrument for measuring mentor skills for postsecondary Science, Technology, Engineering, Mathematics, and Medicine research. The purpose of this study was to revalidate the MCA scale using a larger, more diverse population since the original MCA was validated on a small sample of predominantly senior white male faculty. Methods: The MCA was completed by 1626 mentors from a survey data set of 1759 respondents who participated in eight or more hours of face-to-face Entering Mentoring-based training between 2010 and 2019. We conducted principal component analysis (PCA) with varimax rotation to investigate the internal structure of the MCA and Hatcher's criteria were applied. After a team of mentoring experts independently interpreted the PCA results and reached a consensus on the interpretations of the components, factor analysis and internal consistency reliability analysis were applied to assess the construct validity and the reliability. Results: While the 26-item MCA instrument was originally validated with six subscales, through the factor and reliability analyses, all the parameter estimates for each item of seven components of 24-item MCA were significant and had relatively high internal consistency; the alpha coefficient for the components ranged from 0.77 to 0.86. Conclusions: Five items from the MCA have been dropped, leaving a condensed 21 item scale (MCA-21) which loads onto six competencies, and should now be used to effectively measure mentoring skills. We provide recommendations for furthering the scale development and validation of common measures.