公共政策研擬，尤其環境影響評估，不僅牽涉技術性科學層面，同時涵蓋社會性價值評估與政策性決策判斷。本文旨在探討如何將科學、價值與判斷等因素，合理融合於環境影響評估作業過程，並據此研擬一環境影響評估架構，作為我國環保機關開發案審核依據之參考。所研擬之環境影響評估架構採用之理論基礎，包括社會選擇理論、社會判斷理論及多屬性評估方法。透過社會選擇理論分析說明環境政策制定的民主機制；社會判斷理論解釋科學與價值如何整合於政策制定及其可行性；而多屬性評估方法建立開發案評選的集體決策技術。本文以山坡地開發為例，說明此架構在實例上如何操作。

Public policy making, in particular environmental impact assessment, relies not only on scientific aspects of technology, but also on evaluation of social values and policy decision and judgments making. This paper explores into how to incorporate science, values, and judgments into the process of environmental impact assessment, in order to propose a framework for environmental impact assessment as a basis for policy considerations by environmental protection agencies. The theoretical foundations include social choice theory, social judgment theory, and multi-attribute evaluation methods. Social choice theory depicts the democratic mechanisms for environmental policy making; social judgment theory explains how science and values could be integrated into policy making and feasibility; multi-attribute evaluation methods establish collective decision-making techniques for selection of development projects. Using hillside development cases, I show how this framework works in reality.