COMMUNITY AND INTEREST GROUPS, REPRESENTING UNIQUE PERSPECTIVES AND EXPERIENCE, HAVE OFTEN WORKED TO INTRODUCE NEW IMPACT ASSESSMENT CONSIDERATIONS INTO PLANNING DECISIONS. IMPACT ASSESSMENT REFERS TO FORECASTING THE FUTURE EFFECTS OF A POLICY OR PROJECT IN THE ENVIRONMENTAL, ECONOMIC AND SOCIAL SPHERES. IMPACT ASSESSMENT TECHNIQUES OF VARYING COMPLEXITY ARE DESCRIBED: INCLUDING CHECKLISTS TO HELP STRUCTURE THE SITUATION; IMPASSE (THE IMPACT ASSESSMENT GAME)--A GROUP INTERACTION DEVICE TO STRUCTURE DISCUSSION AND PROVIDE ESTIMATES OF IMPACTS; LAND DIALECTICAL SCANNING--A GROUP DISCUSSION TECHNIQUE FOR IDENTIFYING AREAS OF CONFLICT. OTHER TECHNIQUES INCLUDE THE DELBECQ TECHNIQUE, WHICH CAN BE USED TO GATHER WRITTEN DOCUMENTATION OF SOCIAL IMPACT ASSESSMENT AMONG A GROUP OF NEARLY ANY SIZE; THE DELPHI TECHNIQUE, WHICH MAKES USE OF REPEATED WAVES OF QUESTIONNAIRES AND FEEDBACK REPORTS THAT CONTROL GROUP INTERACTION AND FACILITATE CONSENSUS DEVELOPMENT; AND SCENARIOS AND SURVEYS FOR COMPARISON OF LIKELY IMPACTS OF TWO OR MORE PROPOSALS UPON VARIOUS TARGET GROUPS. IN ADDITION, TREND EXTRAPOLATION OF PAST TRENDS IS USED FOR FORECASTING LARGE-SCALE POPULATION, ECONOMIC, OR OTHER CHANGES, AND COST-BENEFIT ANALYSIS HELPS ESTABLISH THE PROFITABILITY OF A PROJECT. COST EFFECTIVENESS ANALYSIS IS USED FOR DETERMINING UNIT COSTS, AND THE TECHNIQUE OF CROSS IMPACT ALLOWS PREDICTION OF A COMPLEX SERIES OF EVENTS. FINALLY, SIMULATION MODELING PREDICTS THE EFFECTS OF INTERVENTIONS IN LARGE-SCALE URBAN, SOCIAL AND ECONOMIC SYSTEMS, AND INPUT-OUTPUT ANALYSIS, HELPS IN UNDERSTANDING THE STRUCTURE OF A REGIONAL ECONOMY. FIVE OUT OF THE 12 TECHNIQUES WHICH ARE RELATIVELY SIMPLE TO USE AND ARE OF USE TO LOCAL GROUPS ARE THE CHECKLIST, IMPASSE, DIALECTICAL SCANNING, DELBECQ TECHNIQUES, AND THE DELPI TECHNIQUE. A PROJECT COMPARISONS TECHNIQUE IS OUTLINED, WHICH FOCUSES ON PREDICTING IMPACTS THROUGH USE OF INFORMATION ABOUT PREVIOUS, SIMILAR PROJECTS. LOCAL GROUP MEMBERS CAN USE THIS PROCEDURE TO BRING INFORMATION AND EXPERIENCE FROM OUTSIDE THE COMMUNITY TO BEAR ON LOCAL IMPACT ASSESSMENTS. NOTES AND REFERENCES ARE PROVIDED. (DEG)