Inference

Inference is a process whereby a conclusion is drawn without complete certainty, but with some degree of probability relative to the evidence on which it is based.

Survey data may be used for description or for analysis. Descriptive uses include making estimates of population totals, averages, and proportions. Analytical uses include testing hypotheses about the population. The analytical uses involve making statistical inferences. For example, a descriptive use of survey data would be to supply an estimate of the number of male and female engineers. An analytical use would be to infer (based on valid statistical procedures) that there are significantly fewer female engineers than male engineers. Another descriptive use of survey data would be to supply the average salary of teachers. An inferential use would ...