SPECIAL EMPHASIS IS PLACED ON HOW DRUGS ARE OR CAN BE CLASSIFIED AND WHAT KINDS OF DATA, LOGIC, AND ANALYSIS ARE USEFUL AIDS IN DRUG CLASSIFICATION AND RELATED PUBLIC PROGRAM DECISIONS. PARTICULAR ATTENTION IS PAID TO METHODS, AND PROBLEMS WHICH ARISE IN CONNECTION WITH DRUG EVALUATION, CLASSIFICATION SCHEMES, AND THE EVALUATION OF CONTROL PROGRAMS. SPECIAL INTEREST IS TAKEN IN INTERNATIONAL ASPECTS OF DRUG CLASSIFICATION. SEVERAL MAJOR THEMES ARE SOUNDED IN THE BOOK. ONE THEME IS THE STATE OF UNCERTAINTY WHICH CHARACTERIZES ESTIMATES OF DRUG EFFECTS AND THE CONSEQUENT JUDGMENTS WHICH CLASSIFICATION SYSTEMS AND CONTROL PROPOSALS ENTAIL. ANOTHER THEME IS THAT POLICY MAKERS IN THE FIELD OF DRUG LEGISLATION, CONTROL, AND PROGRAMS SHOULD CONSIDER AS MANY ALTERNATIVES AS POSSIBLE. A THIRD THEME IS THE NEED FOR EVALUATION OF DRUG EFFECTS, DRUG LAWS, AND DRUG TREATMENT AND PREVENTION PROGRAMS. THIS VOLUME IS A SUMMARY VERSION OF A MORE DETAILED WORK ENTITLED 'CONTROLLING DRUGS: A HANDBOOK FOR INTERNATIONAL DRUG CLASSIFICATION'. (AUTHOR ABSTRACT MODIFIED)