In this project, the authors explored the application of two common, computer-based test (CBT) designs, computerized adaptive testing (CAT) and linear-on-the-fly testing (LOFT) to two Graduate Record Examination (GRE) Subject Tests chosen to represent the range of different test structures: the GRE Mathematics Test and the GRE Biology Test. The results were mixed. Some variations proved adequate in meeting minimum psychometric requirements. However, no variation proved adequate in the implementation of a complete test blueprint, nor did any variation provide strong support for meeting test security requirements in an environment of unrestricted continuous testing. The conversion of the GRE Subject Tests from paper-and- pencil administration to a computer-based testing format seems viable only if pretesting is implemented, item writing is expanded, test length is reduced, classification schemes are improved, and the roles of test specialists and the Committees of Examiners are substantially revised.