This study sought to examine the nature and dimensions of prior knowledge among undergraduates in an economics course at the Open University of the Netherlands (OuN). A total of 22 law and 55 economics students enrolled in two economics courses were given a 154-item domain-specific knowledge test, which was then analyzed independently by three researchers. The researchers attempted to classify each of the 154 items on each of 10 dimensions (curriculum level, curriculum accent, node relation, behavioral, content, epistemological, number of propositions, information level, and representation level). The results of the analysis indicated that although different dimensions helped to differentiate between law and economics students, the different dimensions were not helpful in identifying more specific and significant contrasts between both student groups. The study also found that the grouping variable "diploma type" was not able to differentiate between levels of mastery of the prior knowledge state. It is foreseen that in situations where there are significant differences between the prior knowledge state of specific subpopulation, the dimensions might be helpful to detect the strengths and weaknesses of the students involved.