APPLICATION OF MEAN AND STANDARD DEVIATION IN QUESTIONNAIRE SURVEYS: CONSTRUCT VALIDATION

Abstract

A simple method using the descriptive statistics involving mean and standard deviation can be applied in questionnaire surveys. By focusing on the reliability and validity assessment, items should have roughly equivalent means and standard deviations within a Likert scale with the rule of thumb of 2:1 (ratio of the maximum standard deviation to the minimum standard deviation). A comprehensive study on the reliability and validity of the questionnaire to assess computer and internet usages is presented to illustrate how to perform a simple evaluation of the item-level descriptive statistics (mean, standard deviation and frequency), the multitrait/multi-item correlation matrix (Pearson correlation and Biserial correlation) and reliability coefficients and inter-scale correlations (Cronbrach’s alpha and Hoyt’s method). This method is thus applicable in any research that employs a questionnaire.