Survey Sampling – How Does It Work?

Survey Sampling – Introduction When it’s not feasible to study an entire target population, a simple random sample is the next best option; with sufficient sample size, it satisfies the assumption of independent and identically distributed variables. And perhaps even more important, it will tend to be nicely representative for the population with regard to […]

SPSS System Variables

Summary SPSS uses a handful of hidden variables for keeping track of things. These so called system variables have names starting with “$” and can be useful in some cases. The most important one is $casenum, the number shown next to each case in the data editor window. SPSS $casenum SPSS $casenum In the left outline of the […]