Scientific progress has long been understood as recombinant, with breakthroughs arising when existing ideas are joined in new ways. Empirical work in this tradition has focused on the inputs to discovery, asking whether a paper draws together atypical or distant prior knowledge. Far less is known about how knowledge is supplied for downstream recombination, or how individual contributions are forged to play distinct and distant roles in the broader system of science. Using citation networks from tens of millions of publications in OpenAlex and the Web of Science, here we show that scientific contributions stably decompose into three functional types, foundations, extensions, and generalizations, distinguishable by the local structure of their forward citations. This decomposition of the 'functional role' of scientific work presents an unseen pattern of scientific production: foundational and extensional work, which respectively build and elaborate within disciplines, dominated the post-war decades but has declined steadily since the early 1990s, while generalizations, meaning compressed and modular contributions reused in distant fields, have risen sharply. Stacked difference-in-differences analyses that exploit venues' transitions to online access and authors' adoption of large language models provide causal evidence that digital knowledge infrastructure is driving this shift. The locus of innovation has thus migrated from within what Simon might characterize as nearly decomposable disciplinary modules to the interfaces between them, recasting the much-discussed decline of disruption as a structural reorganization of science rather than a slowdown, and revealing a growing misalignment between how science now advances and how it is recognized and rewarded.

翻译：长期以来，科学进步被理解为重组式的过程——当既有思想以新方式结合时，突破便应运而生。这一传统下的实证研究聚焦于发现的输入要素，关注一篇论文是否整合了非典型或相距甚远的既有知识。然而，关于知识如何被供给以供下游重组使用，以及个体贡献如何被锻造以在更广泛的科学系统中扮演不同且具有远距离影响的角色，我们知之甚少。本研究利用OpenAlex和Web of Science中数千万篇论文的引文网络，揭示科学贡献稳定地分解为三种功能类型：基础性工作（foundations）、扩展性工作（extensions）与泛化性工作（generalizations）。这三种类型可通过其前向引文（forward citations）的局部结构加以区分。这种对科学工作"功能角色"的分解呈现出一种未见的科学生产模式：基础性工作（在学科内进行建构）与扩展性工作（在学科内进行细化）主导了战后几十年，但自20世纪90年代初以来持续下降；而泛化性工作——即被远方领域重复使用的压缩化、模块化贡献——则急剧上升。利用期刊转向在线访问以及作者采用大语言模型等情境作为准自然实验的堆叠双重差分分析（stacked difference-in-differences）提供了因果证据，表明数字知识基础设施正在驱动这一转变。因此，创新的重心已从西蒙（Simon）可能称之为"近乎可分解的学科模块"内部转移至这些模块之间的界面。这不仅将备受讨论的"颠覆性下降"重新诠释为科学的结构性重组而非停滞，更揭示了科学当前进步方式与其被认可和奖励机制之间日益加剧的错位。