A comparison of static and dynamic presentation procedures on discrimination learning of individuals with severe or moderate mental retardation.

A dynamic presentation of stimulus materials may be more effective than a static presentation. To test this hypothesis, we taught 16 individuals with moderate or severe mental retardation to identify two comparative discriminations (more, longer) by each of two different procedures. In the static, or traditional, presentation procedure the stimuli were positioned before a trial began and not manipulated by the experimenter during the trial. In the dynamic presentation procedure the individual watched the experimenter manipulate the relevant dimension of the stimuli during a series of trials. Both procedures were used in combination with a procedure that relied on fading and on many examples of both the correct and incorrect stimuli across trials. Data were presented in four phases: training, generalization, 1-week maintenance, and 1-month maintenance. No differences in percentage of unprompted correct responses were found between the two procedures in training, generalization, or any of the four maintenance tests. Discussion included possible reasons these results differed from those of prior studies as well as the need for further investigation of the dynamic presentation procedure used with more traditional teaching procedures that rely on extrastimulus prompts.