Within Self-Determination Theory, competence is assumed to be one of three fundamental psychological needs, so the feelings or perceptions of competence with respect to an activity or domain is theorized to be important both because it facilitates peopleÕs goal attainment and also provides them with a sense of need satisfaction from engaging in an activity at which they feel effective. Thus, perceived competence has been assessed in various studies and used, along with perceived autonomy (i.e., an autonomous regulatory style) to predict maintained behavior change, effective performance, and internalization of ambient values.
The Perceived Competence Scale (PCS) is a short, 4-item questionnaire, and is one of the most face valid of the instruments designed to assess constructs from SDT. Like several of the other measures–including the Self-Regulation Questionnaires and the Perveiced Autonomy Support (Climate) Questionnaires–items on the PCS is typically written to be specific to the relevant behavior or domain being studied. The PCS assesses participantsÕ feelings of competence about, say, taking a particular college course, engaging in a healthier behavior, participating in a physical activity regularly, or following through on some commitment. In this packet, there are two versions of the questionnaire concerning the feelings of being able to stick with a treatment regimen and being about to master the material in a course.
Two examples of studies that have used the PSC are Williams, Freedman, Deci (1998) for management of glucose levels among patients with diabetes and Williams and Deci (1996) medical students learning the material in an interviewing course. The alpha measure of internal consistency for the perceived competence items in these studies was above 0.80. Additional examples of the PCS can be found in the SDT web site within the Health Care, SDT packet.
