Many students who enter public schools leave without achieving what has become the expected minimum level of educational attainment, a high school diploma. The purpose of this study was to contribute to existing dropout-prevention research by identifying and validating reliable decision rules for differentiating actual dropouts from high school completers. A review of the literature resulted in the identification of 43 variables being used by different program personnel to identify the potential dropouts. A tally was completed reflecting the number of times each variable occurred across the 100 dropout prevention programs reviewed. Of these programs, 13 specific procedures were found that had necessary conditions for comparison and evaluation. Once the 13 procedures were selected, a search was conducted in the High School and Beyond (HS&B) database for elements that could be used to operationally define the variables listed in each of the 13 selected dropout identification procedures. The operationally defined variables were then used to predict which students in the HS&B database would be dropouts. The results of those evaluations were then compared to known dropout figures available for the HS&B sample. The results suggest that the best procedures for predicting dropouts were the Dropout Prediction Instrument, Potential Dropout Profile, Dropout Prediction Equation, and Identifying Potential Dropouts Scale. (ABL)