本文尝试呈现美国课后服务场域从建立、维持、变革到制度化的百年演化历程。课后服务场域与其他场域的创建过程一样都经历了：从众多行动者在尚未组织化的社会空间中相互竞争和孤立运作，发展为在共同理解的行动框架指导下建立起的高度组织化的集体行动。这些行动者共享着以青年积极发展理念为核心的行动逻辑。它们根据对场域目标与使命的共同理解划定场域边界，并确定与其他行动者之间的关系和地位等级。这些行动者不再以孤立分散形态在场域范围内运作，它们间建立起稳定的联盟关系，在合作中共同为中低收入儿童提供支持性服务。

然而，课后服务场域状态的演变并非自然生成[1]，而是受到大规模社会危机（如大萧条或战争）以及其所嵌套进的国家与非国家场域间复杂关系网络的动态变化等外部冲击的影响。若追本溯源，美国课后服务场域发端于基层民间组织，最初源自于社区组织自发解决本社区儿童放学后无处安全玩耍的场地问题。在这一时期，受到传统社会化理论以及皮亚杰的发展心理学的影响，人们普遍认为儿童是非理性且无目的的弱势群体。他们只有经历一系列预先确定的阶段并在每个阶段中获得相应的认知技能培训后才能顺利发展出成年人所具备的理性能力。[2]因此，儿童被认为无法自我合理安排课后时间的非理性人。他们必须接受成年人精心设计的活动与全方位的指导后才能顺利长成为合格的社会人。在这种观念的指导下，一些社区组织开始为儿童提供有组织的游戏活动，这是课后服务场域萌芽的标志。

随着现代国家在干预经济活动以及社会事务等领域上的权力、力度和范畴日益增强，国家开始逐渐成为讨论任何场域稳定或变革原因时都无法回避的决定性成因。国家在课后服务场域后来的发展、变革与制度化过程中起到了关键性作用。一方面，国家行动者（包括城市市长）的策略行动塑造了课后服务场域的规则、规范以及相关实践做法产生的机会与制约条件；另一方面，他们通过创建有助于新场域秩序稳定再生产的内部治理单位，帮助曾经相互竞争甚至互不相干的行动者之间建立起联盟关系。到了1980年代后期，随着后工业社会特征日益深化、知识经济特征渐露端倪，美国政府愈发重视学生的教育成果，尤其是美国青少年在国际教育考试中的国家排名。对美国霸权地位的担忧直接反映在了21世纪后的教育改革政策。国家行动者对教育场域的干预影响到了课后服务场域的稳定。课后时间不再被视作独立于上学时间的断裂性时间，而被重申为学校学习时间的延伸部分，这催生了多种形态的社区-学校合作伙伴关系模式，如社区学校、延长学习日等（当然，从严格意义上说，这并不是我们所理解的学校教育的延伸，实际上是一种新型的合作教育模式）。在政府对课后时间的重视度日益提高、城市各机构社会资源日渐萎缩以及城市青年学业成绩日益关乎整个国家的经济与民主发展水平的时代背景下，各利益攸关方（无论是课后服务场域内行动者还是外部行动者）都在市政府以及内部治理单位的领导下开始探索能够协调各方主体合作的行动框架。通过倡导各种行动者在共同的目标指引下建立起联盟关系，将校内外资源充分整合，为满足城市低收入儿童的发展需求建立起高效稳定的集体行动形式。

课后服务的制度化也不仅仅是国家行动的特定产物。事实上，课后服务场域具有结构二重性：一方面，它依赖于国家及其邻近场域所提供的物质资源与存在性资源。课后服务场域通过满足国家行动者的政治目标来获取合法性并维持场域稳定。另一方面，虽然对于“何为课后服务，什么是好的课后服务，以及如何提供高质量的课后服务”等问题的竞争性阐释从未终结，但出身基层的传统课后服务组织有着自己的能动性选择偏好。它们会为自己所支持的价值理念而与其他场域所引入的挑战者群体相博弈。课后服务场域能够在一定程度上摆脱国家政治利益与意识形态的完全控制，就在于它与社区间建立起了紧密联系。正是通过建立多重联盟关系，它们才能在政治与经济场域所提供的结构性制约中找到可以发起挑战的裂缝：在与学校的政治合作关系中，通过坚守并充分阐释青少年积极发展理念，形成了一套新的文化理解并重新建构了合作成员间的共享利益与身份认同，进而潜移默化地诱使学校教育模式发生变革。

[1] 自然生成视角认为制度化是“一种自然的、没有受到人的指引的过程”（见Strang & Sine, 2002: 52）。

[2] Allison James and Alan Prout.Constructing and Reconstructing Childhood:Contemporary Issues in the Sociological Study of Childhood.Taylor & Francis e-Library,2005.

This paper attempts to present the century long evolution process of the American after-school service field from establishment, maintenance, transformation to institutionalization. The process of creating after-school service fields, like other fields, has gone through: from numerous actors competing and operating in isolation in an unorganized social space, to highly organized collective actions established under the guidance of a common understanding framework of action. These actors share an action logic centered around the concept of positive youth development. They delineate the boundaries of the field based on a common understanding of its objectives and mission, and determine the relationships and status levels with other actors. These actors no longer operate in an isolated and dispersed form within the field, but establish stable alliance relationships between them and work together to provide supportive services for low - and middle-income children in cooperation.

However, the evolution of the state of the after-school service field is not naturally generated, but is influenced by external shocks such as large-scale social crises (such as the Great Depression or war) and the dynamic changes in the complex network of relationships between national and non-state fields embedded within them. If we trace back to the origin, the after-school service field in the United States originated from grassroots civil organizations, initially originating from community organizations spontaneously solving the problem of children in their community having no safe place to play after school. During this period, influenced by traditional socialization theories and Piaget's developmental psychology, people generally believed that children were irrational and purposeless vulnerable groups. They can only develop the rational abilities possessed by adults smoothly after going through a series of predetermined stages and receiving corresponding cognitive skills training in each stage. Therefore, children are considered irrational individuals who cannot arrange their after-school time on their own. They must accept carefully designed activities and comprehensive guidance from adults before they can smoothly grow into qualified social individuals. Under the guidance of this concept, some community organizations have begun to provide organized game activities for children, which is a symbol of the budding after-school service field.

The institutionalization of after-school services is not just a specific product of national action. In fact, the after-school service field has a structural duality: on the one hand, it relies on the material and existential resources provided by the country and its neighboring fields. The after-school service field obtains legitimacy and maintains field stability by meeting the political goals of national actors. On the other hand, although the competitive interpretation of "what is after-school service, what is good after-school service, and how to provide high-quality after-school service" has never ended, the traditional after-school service organizations from the grass-roots level have their own dynamic sexual selection preferences. They will compete with challenger groups introduced in other fields for the values they support. The after-school service field can to some extent break free from the complete control of national political interests and ideology, because it has established close connections with the community. It is through the establishment of multiple alliance relationships that they can find cracks in the structural constraints provided by the political and economic fields that can initiate challenges: in the political cooperation relationship with schools, by adhering to and fully explaining the concept of positive development of young people, a new cultural understanding has been formed and the shared interests and identity of cooperative members have been reconstructed, which subtly induces changes in the school education model.