Abstract
It is argued that the development of self-efficacy represents a central aspect of development in adolescence for 3 reasons. First, self-efficacy is an important predictor for actual efficacy and, thus, is a major component of the individual's ability to act suc-cessfully. Second, self-efficacy is a major action-guiding aspect of the self-concept. Third, both aspects can be combined in an action model of personality, which provides the framework for the development of a standardized questionnaire for self-efficacy and externality from a personality psychology point of view. To validate this questionnaire, a study was conducted with 215 New Zealand and 221 German secondary school students ages 16 to 17 years using a German and an English version of the inventory. Item parameters as well as scale parameters of the English and the German versions of the inventory, were satisfactory and comparable. First validity analyses reveal no significant scale differences for girls versus boys; no significant scale differences between New Zealand and German adolescents; and some rather weak, but significant, positive correlations of self-efficacy to academic performance and perceived classroom climate.