Research Of Non-sampling Error On Marketing Research Based On Inquiry Approach

At the present stage, marketing research has become more and more important with much competition on markets. Over time better research methods have been developed to produce more reliable strategic and tactical assessments for successful marketing campaigns. But along with the extensive application of marketing research, the quality of survey has been regarded as an important problem by experts, scholar and researchers in this field. The main reason influencing the marketing research project is error, and there are two types of error in the investigation: sampling error and non-sampling error. Sampling error is always followed with sampling, but it can be calculated and controlled. Non-sampling errors occur from non-response, coding, computer processing, sampling frame, reporting, and others. In this thesis, it attempts to analyze non-sampling together with psychological testing theory and multivariate statistical theory in the field of marketing investigation. It also attempts to find the main reasons which result in non-sampling error on the base of analyzing steps of investigation after defining the meaning of non-sampling error, and bring forward some simple methods of testing non-sampling error, previous, in the middle and posterior control and solution of non-sampling error in the stages of the process of investigation by using the methods of statistical grouping and comparison to diminish non-sampling error and improving the quality of investigation data.