Survey Methodology is becoming a more structured field of research, deserving of more and more academic attention. The SAGE Handbook of Survey Methodology explores both the increasingly scientific endeavour of surveys and their growing complexity, as different data collection modes and information sources are combined. The handbook takes a global approach, with a team of international experts looking at local and national specificities, as well as problems of cross-national, comparative survey research. The chapters are organized into seven major sections, each of which represents a stage in the survey life-cycle: Surveys and Societies Planning a Survey Measurement Sampling Data Collection Preparing Data for Use Assessing and Improving Data Quality The SAGE Handbook of Survey Methodology is a landmark and essential tool for any scholar within the social sciences.
Chapter 37: Dealing with Missing Values
Dealing with Missing Values
Most data sets are affected by missing values, i.e., data values of scientifically interesting variables that are assumed to exist but are not observed and can not deterministically be derived from observed values. This characterization is not a clear-cut definition of the phenomenon of missing values, but it includes the most common situations. Examples are unanswered questions or not reported reactions of statistical units in general, values which are not observed because units are exposed only to parts or blocks of a larger questionnaire (‘missings by design'), if impossible or implausible values are deleted, or, in the context of causal inference and non-experimental settings, when units are observed only under one of two (or ...