The aim of this research was to identify, develop, and evaluate empirically new reasoning item types that might be used to broaden the analytical measure of the Graduate Record Examinations (GRE) General Test and to strengthen its construct validity. Six item types were selected for empirical evaluation, including the two currently used in the GRE analytical measure. Two experimental batteries, one using a three-option format and the other, a multiple yes-no format, were administered to 2 samples of approximately 370 examinees each. Item analyses and analyses of sex differences, criterion-related validity, and relationships of the experimental item types to the current GRE measures were conducted. All but one of the experimental item types exhibited promise for strengthening the GRE analytical measure, and even the one exception appeared to be a possible item type for the GRE verbal measure. Different combinations of the item types were evaluated in a series of confirmatory factor analyses, supplemented by correlational analyses and an exploratory factor analysis. The study also provided evidence that the reasoning domain consists of two major subdomains: informal reasoning and formal-deductive reasoning. Nineteen tables present analysis results. Three appendixes give examples of the experimental item types, list participating test centers, and present correlation matrices. Appendix C contains eight tables. (Contains 41 references.) (Author/SLD)