Information technology can enhance the effectiveness of the part of the laboratory testing loop that occurs outside of the clinical laboratory. That external component involves the presentation of laboratory results and related information to physicians and the reception of physician requests for follow-up testing. Improvements made in the clinician-computer interface can conceivably enhance the quality of information transfer of this part of the testing loop and thereby improve the effectiveness of the entire loop. Our experience has been that results presentation is easier to address than order reception and that the economic benefits from improved result presentation can be substantial. Improving order reception requires more finesse, especially with the limitations of today's health systems and their information systems in mind. For instance, effective computer-based management of prospectively developed orders (eg, clinical protocols) not only can have a substantial positive impact on test use, but is actually welcomed by clinicians. Application of information technology at the clinician-computer interface has good potential to foster more appropriate use of clinical laboratory resources.