Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


The purpose of this study was to develop and evaluate a tutorial computer-assisted instruction (CAI) lesson teaching the normal distribution and standard scores. Instruction on the normal curve, and unit-normal curve, z-scores, areas under the normal curve, and standard scores was given in this study. This CAI courseware was created in order to teach or review these concepts to graduate students in education. An evaluation of this CAI lesson was conducted. It consisted of a small scale pilot test, and a 2 x 3 factorial design experiment. The pilot test study was conducted so that reaction data to this software package could be collected and utilized in revising this software. The 2 x 3 factorial design experiment was conducted to determine which of three management strategies for this CAI lesson is most effective for a given level of aptitude. The two quantitative aptitude levels were low-aptitude and high-aptitude levels. The participants' median score on the quantitative portion of the Graduate Record Examination (GRE) was used to determine low-aptitude and high-aptitude. The three management strategies were learner-control, program-control with a mastery criterion and advisement, and program-control with neither a mastery criterion nor advisement. The following conclusions were drawn on the basis of the findings in this study. (1) The mean of the posttest scores for the group of participants in the pilot test study was significantly higher than the mean of their pretest scores. (2) High-aptitude learner-control students had a significantly higher posttest mean score than low-aptitude learner-control students in the 2 x 3 factorial design experiment. (3) The data collected in this study indicated a trend of assigning low-aptitude students to a program-control management strategy. (4) Gagne's cognitive theory of learning was effectively utilized in the development of this courseware. An analysis of the data collected in this study, including the statistical comparison of pretest and posttest scores, indicated that this CAI package was effective in teaching its defined objectives.