Number Concepts; Measurement; Geometry; Probability; Statistics; and Patterns, Functions and Algebra. Procedural Errors were further categorized into the following content categories: Computation; Measurement; Statistics; and Patterns, Functions, and Algebra. The results of the analysis showed the main sources of error for 6th, 7th, and 8th grade students were Conceptual errors and Problem Solving errors. Although the percentage of responses which were incorrect was different for each pass level, the percentage of incorrect responses due to Problem Solving Errors was similar regardless of grade level and pass level. The percentage of students who choose incorrect responses due to Conceptual errors was similar across all grade levels and pass levels. However there were differences in the Content categories for Conceptual errors. The percentage of students who choose incorrect responses due to Procedural errors was similar across all grade levels and pass levels. There were also differences in the Content categories for Procedural Errors. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]