An all too frequent characteristic of research data is that some of the values called for by the substantive issues being addressed are missing for some subjects. This can occur for many reasons, to varying degrees, and in various patterns. It can be so serious that different investigators analyzing the same data files may come to different conclusions just because they have chosen different methods of coping with missing data. In this chapter we list some of the considerations that enter into decisions about handling missing data and review contemporary methods.
11.1 BASIC ISSUES IN HANDLING MISSING DATA
11.1.1 Minimize Missing Data
It is almost always possible to keep the amount of missing data down by thorough preparation ...