Nonresponse in survey research and double sampling

m NONRESPONSE IN SURVEY RESEARCH AND DOUBLE SAMPLING TECHNIQUE (M.Sc. Thesis) Aylin ALKAYA GAZI UNIVERSITY INSTUTE OF SCIENCE AND TECHNOLOGY May 2003 ABSTRACT In survey researches a distinction between two major types of missing data in surveys due to nonresponse had been made. First type is, unit nonresponse; for some sample units no entire data is available. The second type is, item nonresponse; sample unit or units have missing data for one or more questions or variables. In this study, unit nonresponse and its sources, reasons, what it caused was tried to be investigated. Nonresponse reduce the quality and reliability of the estimates. The parameter estimates that only depend on respondents will be biased because of the difference between nonrespondents and respondents. In researches the existence of nonrespondents, cause a decrease in sample size and an increase in research costs. For this reason, to prevent nonresponse occurance efforts must be carried out and in its presence, to minimize its effects on estimations, corrections must be done. In this study, the double sampling method, which is one of the suggested methods for removing nonresponse bias and increasing response ratio, was evaluated to guide for many researches. In thesis, in double sampling method for nonresponse, the response and nonresponse units were classified into different clusters and one random subsample was taken from nonresponse cluster. From the taken subsample, compared to first sample, besides a data collection methodIV that more efforts are spend to get answers from nonresponse units, some different methods are used to set answers. different methods are used to get answers. Science Code : Key Words : nonresponse, unit nonresponse, double sampling Page Number: 165 Adviser : Professor Dr. A. Alptekin ESİN