Description of a restricted randomization program (RRP)

A computer program, which produces restricted randomizations of numbers as an aid in counterbalancing large experimental designs, is described. The input to the program is a series of specifications for sampling a pool of random numbers. For example, it might be specified that each number in the pool be selected at least once and not more than twice in each replication of the experiment. The output would be a restricted randomization meeting these specifications. The program has been used in several memory experiments and could be used in other experimental paradigms in learning and perception.