Inferential statistics are a series of measures that allow a researcher to make predictions as to the relationship between variables. Methods vary based on the type of data and the goals of the analysis, but the goal of the analysis is to use one variable to efficiently predict another. Inferential analysis starts with the predicted relationship, develops variables, refines the variables and model, designs the experiment, and runs the appropriate statistics. This entry discusses models and hypotheses, variables, conditions and limitations, experimental design, and major tests.