為探討在電腦輔助協作學習環境的提問鷹架設計對學生進行社會性科學議題決策學習之影響，本研究利用封閉性問題和開放性問題，設計混合提問鷹架與開放性提問鷹架兩種線上教學模組，以準實驗研究法隨機分派一所高中二年級學生參與水庫和綠建築兩個議題，各為期4節課的決策學習。兩種模組各41份有效樣本在發電議題前測決策表現沒有顯著差異；但學生的水庫議題學習單顯示，混合提問鷹架模組學生的決策表現顯著優於開放性提問鷹架模組的學生；而綠建築議題學習單，則兩種模組學生的決策表現無顯著差異；但核能議題後測的決策表現，開放性提問鷹架模組學生顯著優於混合提問鷹架模組的學生，並且低決策能力學生與高決策能力學生之間的表現落差已不顯著。此結果反映在協作學習環境中的開放性提問鷹架提供學生適當挑戰，能增進其決策表現的學習表現。

To explore the effects of question prompt scaffolding on students’ decision-making on socio-scientific issues in a computer-supported collaborative learning environment, this study designed a SSI online module with open-ended question prompts and another module mixed with open-ended or close-ended question prompts. Using the quasi-experimental research method, the 11th-grade classes in a senior high school were randomly assigned to two modules to learn about the decision-making on issues of water reservoir and green building lasting for four class periods. The results of 41 valid samples showed no significant difference found between the performances on the pretest about electricity supply of students in the two modules. Regarding their performances on the tasks in the first water-reservoir issue, the students in the module with mixture design performed significantly better than those in the module of open-ended question prompts. However, no significant difference was found between the performances on tasks about the second green-building issue of students in the two modules. Moreover, in the posttest about nuclear power issue, the students in the module of open-ended question prompts performed better than those in the module with mixture design. In addition, the performance gap between the students with low decision-making ability and high decision-making ability was no longer obvious. It is suggested that in the collaborative learning environment, open-ended question prompts provide certain optimal challenges that can significantly promote students’ performances on decision-making.