ABSTRACT
This assignment illustrates several of the methods for computing instrument reliability. Internal consistency reliability, for multiple item scales. In this assignment, we will
compute the most commonly used type of internal consistency reliability, Cronbach’s coefficient alpha. This measure indicates the consistency of a multiple item scale. Alpha is typically used when you have several Likert-type items that are summed to make a composite score or summated scale. Alpha is based on the mean or average correlation of each item in the scale with every other item. In the social science literature, alpha is widely used, because it provides a measure of reliability that can be obtained from one testing session or one administration of a questionnaire. In problems 4.1, 4.2, and 4.3, you compute alphas for the three math attitude scales (motivation, competence, and pleasure) that items 1 to 14 were designed to assess.
