Well, remember that the basic interpretation of NA is “I don’t know what this number is”. This means that 1 + NA = NA: if I add 1 to some number that I don’t know (i.e., the NA) then the answer is als...Well, remember that the basic interpretation of NA is “I don’t know what this number is”. This means that 1 + NA = NA: if I add 1 to some number that I don’t know (i.e., the NA) then the answer is also a number that I don’t know.
Missing data can be the source of a lot of tricky issues, most of which I’m going to gloss over. However, at a minimum, you need to understand the basics of handling missing data in SPSS. Let’s start ...Missing data can be the source of a lot of tricky issues, most of which I’m going to gloss over. However, at a minimum, you need to understand the basics of handling missing data in SPSS. Let’s start with the simplest case, in which you’re trying to calculate descriptive statistics for a single variable that has missing data. Note that although there are four cases in the data set, only 3 are valid, so SPSS uses only the valid cases when computing the descriptive statistics.
