Cognitive Therapy and Research, Vol. 9, No. 6, 1985, pp. 631-649 Levels of Attribution and Change (LAC) Scale: Development and Measurement I John C. Noreross 2 University of Scranton James O. Prochaska University of Rhode Island Martin Hambrecht University o f Freiburg This article describes the construction and initial validation of the Levels of Attribution and Change (LAC) Scale, a 60-item instrument that assesses the levels and loci of causal attributions about a self-selected problem. A rational internal scale construction method was employed in which judges' ratings and principal component analyses resulted in 10 robust scales: Spiritual De- terminism, Biological Inadequacies, Bad Luck, Environmental Difficulties, Maladaptive Cognitions, Familial Conflicts, Interpersonal Conflicts, Intraper- sonal Conflicts, Chosen Lifestyle, and Insufficient Effort. The 10 compo- nents accounted for 67.5% of the total variance. Internal consistency coefficients ranged between. 79 and. 92 (M = . 87). A cluster analysis yield- ed 10 distinct subject profiles, which resemble common attributional pat- terns. Second-order analyses revealed two underlying dimensions labeled Internal-Dispositional and External-Situational. It is concluded that the LA C Scale is an internally consistent, multidimensional inventory with consider- able potential use, although additional normative and validity data are needed before operational use. The theoretical and clinical implications of these find- ings and possible applications of the instrument are discussed. ~The authors gratefully acknowledge the contributions of Wayne F. Velicer and Carlo C. DiClemente throughout this study. This research was supported in part by Grant CA 27821 from the National Cancer Institute. 2Address all correspondence to John C. Norcross, Department of Psychology, University of Scranton, Scranton, Pennsylvania 18510. 631 0147-5916/85/1200-0631504.50/0© 1985 Plenum Publishing Corporation