批判性思维是对个体具有重要意义的高级思维能力，可以帮助个体有效利用不同的信息做出最优化的决策，并根据不同的情景和可能性对计划进行调整。大学生正处于高水平思维的快速发展期，同时也是从学校走向社会的过渡期，他们需要主动思考如何将知识的积累转化成解决实际问题的能力，因此批判性思维是大学生必需的高级思维能力，批判性思维的教学也成了21世纪高等教育的重要目标。国外学者对批判性思维的测量和干预进行了广泛而持续的研究，大部分干预持续时间较短，而且由于课堂的限制无法提供真实的问题环境，因此在批判性思维干预的有效性上仍存在争议，且其中的机制尚不明晰。服务学习是一种起源于美国的教学法，有效的服务学习具有互惠性、主动性、开放性、反思性等特征，能够帮助学生在真实的问题解决环境中获得直接的体验，通过小组合作来促进认知能力和社会能力的发展，同时教师的支持性反馈可以促进学生在活动中不断重新认识问题并对方案进行反思和改进，从而促进他们解决问题能力和高级思维能力的发展（Billig，2002）。已有研究证实了服务学习对批判性思维的促进作用，多采用自我报告的方式，较少考察在批判性思维不同维度上服务学习的作用有何不同，同时服务学习作为一种长时的教学干预，已有研究中没有考察在服务学习不同阶段批判性思维的动态变化趋势。本研究组织心理学专业本科生进行了两次为期8-10次的服务学习活动，探讨服务学习对大学生批判性思维能力的促进作用。研究一在服务学习前后利用自编批判性思维表现编码表对被试在结构不良情境问题中的回答进行编码，来考察服务学习对大学生批判性思维能力的促进作用。研究二采用服务学习过程中的反思日志做为材料，利用自编批判性思维表现编码表对被试在反思日志中开放问题的答案进行编码，来探讨服务学习各阶段批判性思维能力的变化趋势以及各维度之间的差异。研究三给予服务学习中的学生反思支架，探讨反思支架对服务学习对批判性思维能力促进作用的影响。研究的主要结论如下： （1）服务学习前后相比大学生批判性思维能力有显著提高在方案改进维度上变化显著，在改进方案的针对性和改进依据的客观性分维度上变化显著。 （2）在服务学习各阶段被试的批判性思维能力整体呈稳步上升趋势。 （3）在服务学习不同阶段被试在不同维度上的批判性思维表现存在差异。被试在方案评价维度上的批判性思维表现在阶段1至阶段2呈上升趋势，阶段2至阶段3差异不显著；在方案改进维度上在阶段1至阶段2、阶段2至阶段3均显著上升。 （4）在服务学习3个阶段被试的“评价依据客观性”和“改进依据客观性”两个分维度上均呈显著的上升趋势，表明被试利用证据的能力上升。 （5）在服务学习中反思支架对被试的批判性思维能力变化有显著影响，提供反思支架的小组批判性思维能力变化更为显著，具体体现在改进方案的针对性和改进方案的有效性两个分维度。

Critical thinking is a kind of high-level thinking skill，it's important to individuals as helping us effectively making us of different kinds of information，and adjusting plans according to different situations and possibilities. College students are in a period of rapidly developing of high-level thinking and transition from school to outside world, they need to take the initiative to think about how could the accumulated knowledge be translated to the ability to solve practical problems, so critical thinking is an essential skill of college students, and teaching of critical thinking has become an important goal of higher education in the 21st century. Foreign researchers studied extensively about the measurement and intervention of critical thinking, but due to the short duration and the inveracity problem situation, controversial still remains about the effectiveness of intervention , and the mechanism inside is not clear yet. Service learning is a pedagogy emphasizing mutually benefit, initiative, openness, and reflection, can help students gain direct experience in real situations, and promote individual development of cognitive and social skills through group cooperation, and during the process teachers' supportive feedback can help students continually recognize the problem and evaluate and improve the solution, so then enhance their skills of problem-solving and high-level thinking ability. Researchers have suggested service learning can enhance critical thinking, most using self -reported method, few discussed the different effect of service learning on different dimensions of critical thinking, and few studied the changing trends of critical thinking in different stages of service learning. In this study, undergraduate students majored in psychology were organized to service learning activities to discover the effect of service learning on critical thinking. In Study One 109 students were investigated with California Critical Thinking Disposition Inventory, and non-structural situational questions were used as experimental materials, and self-compiled critical thinking performance coding schedule was used to encode materials collected pre-post the service learning process. In Study Two open questions in reflective journals were used as experimental materials to be encoded during the service learning process. The main conclusions are as follows: (1) Students' critical thinking skills was significantly improved after service learning , especially on the dimension of solution improvement. (2) In all stages of service students' critical skills was steadily improved .（3）The difference was significant between students' improvement on different dimensions of critical thinking performance. The means on solution evaluation increased significantly in stage 1 to stage 2, the change was not significant in stage 2 to stage 3,the means on solution improvement increased significantly in stage 1 to stage 2 and stage 2 to stage 3. （4）Students' ability to efficiently make use of evidence increased.（5）During the service learning process，reflective scaffolding can significantly effects students' improvement critical thinking performance, specially on the solution improvement dimension.