Procedure
Teachers administered a 49-item inventory to the subjects during their classes. Four months later, the inventory was re-administered to 64 subjects who had previously taken the survey.
Results
The value of alpha was .96 for the 49 items, showing a high degree of internal consistency. An item deletion process was performed in order to increase the value of alpha. Items were deleted based on their item-to-total correlation. Nine items had correlations lower than .50. Items were deleted one at a time starting with the one with the lowest item-to-total correlation. After deleting these nine items, alpha reached a value of .97.