Determination of Reliability and Validity Measures of a Questionnaire

A questionnaire is a series of questions asked to individuals to obtain statistically useful information about a given topic. When properly constructed and responsibly administered, questionnaires become a vital instrument by which statements can be made about specific groups of people or entire population. Questionnaires are frequently used in quantitative marketing research and social research. They are a valuable method of collecting a wide range of information from a large number of individuals, often referred to as respondents. Adequate questionnaire construction is crucial to the success of a survey. Inappropriate questions, incorrect ordering of questions, incorrect scaling, or bad questionnaire format can make the survey valueless, as it may not accurately reflect the views and opinions of the participants. A useful method for checking a questionnaire and making sure it is accurately capturing the intended information is to pretest the 'reliability' and 'validity' of the questionnaire. In this paper we have evaluated the 'reliability' and 'validity' of the 'socio-economic status scale questionnaire'. Socio- economic status scale questionnaire was used to analyze the social and economic background of the students of class VIII. The questionnaire was designed to asses the effect of Socio-economic status of the parents on the interest of the upper primary students in mathematics. The questionnaire covered three areas viz. education of father, occupation of father and monthly family income. Total 384 sample from different types of schools of Guwahati were selected for the purpose. The internal reliability and validity were examined. The formulae used for internal reliability were Split-half reliability and Cronbach Alpha etc.