Summated scales are more than frequently used in the different survey instruments so ad to probe into the underlying constructs which the researcher wishes to measure. These may vary from indexed responses to multi point questionnaires which have to be at a later stage complied together to arrive at a resultant score of each respondent. The development of such scales is not the end of research in itself, rather it is a means to gather and compile predictor variables so as to use them in objective models. One of the most commonly used reliability statistics in today’s time is Cronbach alpha. It assists in determining the internal consistency of the items in a survey in order to gauge its reliability.
Reliability does come in the forefront when the various variables that have been developed for summative scales are to be used as predictor components. Summated scales are a compilation of different interrelated items that have been designed to measure the various underlying constructs. The variables that have been derived from the different test instruments can be called reliable when they offer reliable responses over a repeated administration of the test.
Cronbach Alpha is a numeric coefficient of reliability. The Computation of Alpha is dependent upon the reliability of a test relative to different other tests. The range of the alpha co efficient is between 0 to 1and is used to describe in a simple way, the reliability of the different factors that have extracted from a dichotomous questionnaire or scale. The higher the score within the range of 0 to 1, the greater is the reliability of the scale. 0.7 is the acceptable reliability score of Cronbach alpha