A simulation laboratory for statistics

In this paper, we describe a general purpose data simulator, Datasim, which is useful for anyone conducting computer-based laboratory assignments in statistics. Simulations illustrating sampling distributions, the central limit theorem, Type I and Type II decision errors, the power of a test, the effects of violating assumptions, and the distinction between orthogonal and non-orthogonal contrasts are discussed. Simulations illustrating other statistical concepts—partial correlation, regression to the mean, heteroscedasticity, the partitioning of error terms in splitplot designs, and so on—can be developed easily. Simulations can be assigned as laboratory exercises, or the instructor can execute the simulations during class, integrate the results into an ongoing lecture, and use the results to initiate class discussion of the relevant statistical concepts.