Purpose: This article outlines the development and validation of the Need-Relevant Instructor Behaviors Scale (NIBS). Drawing from self-determination theory, the NIBS is the first observation tool designed to code the frequency and the intensity of autonomy-, competence-, and relatedness-relevant behaviors of exercise instructors. The scale also captures the frequency of need-indifferent behaviors. Methods: The behaviors of 27 exercise instructors were coded by trained raters on two occasions, before and after they received training in adaptive motivational communication. Results: Findings supported the structural validity and reliability of the scale. The scale’s sensitivity to detect changes in frequency and intensity of need-relevant behaviors was also evidenced. Conclusions: The NIBS is a new tool that offers a unique, tripartite assessment of need-relevant behaviors of leaders in the physical activity domain.
Quested, Ntoumanis, and Thogersen-Ntoumani are with the School of Psychology, Curtin University, Perth, Australia. Stenling is with the Dept. of Psychology, Umeå University, Umeå, Sweden. Hancox is with the Div. of Rehabilitation and Ageing, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom.