近年來，塑膠污染問題日益受到全球關注，其所造成的環境衝擊已成為永續發展的重要挑戰之一。為減少一次性塑膠製品的使用並培養民眾的環境責任感，減塑教育逐漸成為環境教育的重要推動方向。然而，過去相關研究多聚焦於知識、態度及行為改變的評估，較少探討減塑教育所創造的整體社會價值。因此，本研究以社會投資報酬率（Social Return on Investment， SROI）為評估工具，探討校園減塑教育計畫所產生之社會影響與社會價值。 本研究以臺灣某非營利組織推動之校園減塑教育計畫為研究對象，依循SROI方法進行分析，包括界定研究範圍與利害關係人、建立影響地圖、蒐集成果證據與賦予價值、建立影響力、計算社會投資報酬率。研究對象涵蓋學生、家長、教職員及機構等主要利害關係人，透過問卷調查蒐集各利害關係人參與計畫後所產生之成果資料，並運用財務代理變數將無法直接以市場價格衡量之成果進行貨幣化。為提升評估結果之可信度，本研究進一步納入反事實因子、歸因因子、移轉因子及衰退因子等影響力調整機制，以評估計畫所帶來之實際效益。 研究結果顯示，減塑教育計畫對不同利害關係人皆產生多面向的正向影響。學生在自我反思能力、恆毅力、環境責任感、減塑行動積極性及群體歸屬感等方面有所提升；家長在環境責任感、家庭互動及環境學習意願方面獲得改善；教職員則在減塑教育推廣意願、教學熱忱及永續責任感方面展現正向改變；機構亦於減塑氛圍、永續形象及社區合作等面向獲得效益。研究結果顯示，減塑教育所產生之影響已超越環境知識與行為層面，進一步延伸至個人成長、家庭互動、教育實踐及組織發展等多元價值。 本研究透過SROI方法系統性評估減塑教育計畫之社會價值，除補充環境教育領域對社會影響評估之研究缺口外，亦可作為政府機關、教育單位及非營利組織推動環境教育與資源配置之參考依據，並提供未來相關研究進行社會價值衡量之實務參考。;Plastic pollution has become an increasingly important global environmental issue and represents a major challenge to sustainable development. To reduce the use of single-use plastics and foster environmental responsibility among the public， plastic reduction education has become a key component of environmental education initiatives. However， previous studies have primarily focused on evaluating changes in environmental knowledge， attitudes， and behaviors， while relatively little attention has been paid to the broader social value generated by such educational programs. Therefore， this study applies the Social Return on Investment (SROI) framework to examine the social impacts and social value created by a school-based plastic reduction education program. This study investigates a plastic reduction education program implemented by a non-profit organization in Taiwan. The analysis follows the SROI framework， including establishing the scope and identifying stakeholders， developing an impact map， evidencing and valuing outcomes， establishing impact， and calculating the SROI ratio. The primary stakeholders include students， parents， school staff， and participating institutions. Outcome data were collected through questionnaire surveys， and financial proxies were employed to monetize outcomes that could not be directly valued through market prices. To improve the credibility of the evaluation， impact adjustments were conducted by incorporating deadweight， attribution， displacement， and drop-off factors to estimate the actual effects generated by the program. The findings indicate that the plastic reduction education program generated a wide range of positive outcomes across different stakeholder groups. Students demonstrated improvements in self-reflection， grit， environmental responsibility， motivation to engage in plastic reduction actions， and sense of community. Parents experienced enhanced environmental responsibility， family interaction， and willingness to learn about environmental issues. School staff showed increased motivation to promote plastic reduction education， greater teaching enthusiasm， and a stronger sense of sustainability responsibility. Participating institutions also benefited through improvements in sustainability culture， organizational image， and community collaboration. The results suggest that the impacts of plastic reduction education extend beyond environmental knowledge and behavioral change， contributing to personal development， family relationships， educational practices， and organizational development. By systematically evaluating the social value of a plastic reduction education program through the SROI framework， this study contributes to the growing body of research on social impact assessment in environmental education. The findings may serve as a useful reference for governments， educational institutions， and non-profit organizations in the development of environmental education policies， resource allocation decisions， and future social value assessments.
