APA Dictionary of Psychology

the distribution of a statistic, such as the mean, obtained with repeated samples drawn from a population. Simulation studies allow researchers to specify known population information, conduct a very large number of repeated draws on the population, and build an empirical distribution of the statistic based on these draws (e.g., t, F, or χ² distributions). For example, the means calculated from samples of 100 observations, repeatedly and randomly drawn from the population, yield a sampling distribution for the mean. Knowledge about the distribution of a statistic allows researchers to say when a finding from a sample is unusual (e.g., statistically significant) and when it would be expected from the statistic’s known behavior, thus enabling the sampling distribution of a statistic to be used in testing hypotheses about variables and their relationships. See also inferential test.