title: Random without replacement is not random: Caveat emptor.
abstract: The vast majority of psychology labs rely on prepackaged software applications (e.g., E-Prime) for the programming of experiments. These programs are often used for stimulus selection, and many use a selection method referred to as random without replacement. We demonstrate how random without replacement deviates from random selection, and we detail selection biases that result. We also demonstrate, in a simple experiment, how these selection biases, if left unchecked, can influence behavior. Recommendations for reducing the impact of these biases on performance when random without replacement is used are discussed.
authors.affiliation: University of California, Berkeley, California 94720, USA. cblais@berkeley.edu
authors.forename: Chris
authors.initials: C
authors.lastname: Blais
mesh_terms: D006801:Humans; D008960:Models, Psychological; D011584:Psychology / Q000379:methods*; D011930:Reaction Time