The dimensionality and reliability of Rotter's internal-external control scale was examined using Australian students. The results imply that the scale is not additive but multidimensional. Two distinct largely independent factors relating to personal and political control beliefs were extracted. General control concerns the belief that a person has mastery over his own life while political control includes items which measure the extent to which an individual is capable of having an influence on political institutions or the course of world affairs. On retesting, 8 of the 9 General Control items loaded on the same first factor. All 5 of the Political Control items loaded on the second factor. Test-retest reliability of the I-E scale was.61. These results suggest that the Rotter Scale itself, and its two factor structure, are stable over a considerable period of time.