Although drinking behavior is clearly a central dependent variable in alcoholism treatment research, the field has reached no consensus on measurement methodology for alcohol consumption. At least four methods for quantifying consumption have been commonly used in outcome studies: quantity-frequency questions, average consumption grids, timeline follow-back and self-monitoring. The Form 90 family of structured interviews was developed by collaboration among the Project MATCH investigators, combining the strengths of prior assessment methodologies. The development, structure, supporting software and training approaches for the Form 90 instruments are described.