What do self-efficacy items measure? Examining the discriminant content validity of self-efficacy items.

Self-efficacy items vary in terms of their content validity with only some of the items assessed providing 'pure' measures of the self-efficacy construct. Item wording should be considered during study design to avoid misinterpretation. Statement of contribution What is already known on this subject? For decades, questions have been raised relating to the content validity of self-efficacy scales, with suggestions of possible construct contamination. Previous studies have shown that manipulation of the wording of self-efficacy scale items results in varied participant interpretations. While self-efficacy items have been found to be distinguishable from other similar constructs, it is equally important to ensure that they are uncontaminated by different constructs within the same theory. Otherwise, when the theory is used to investigate behaviour, variance attributable to self-efficacy may be attributed to a different construct or vice versa. The present study uses discriminant content validation to test this and a think-aloud study to explore participants' interpretation of classic self-efficacy items. What does this study add? The study uses discriminant content validity methodology to assess the content validity of self-efficacy scales. Self-efficacy items which are contaminated with content from other constructs are identified. Information is presented on 'pure' self-efficacy items which can be used to guide item selection in future studies.