Shaping scientific careers: the role of early-career research topic dynamics in fostering novel knowledge
基于270位生命科学领域中年科学家的调查数据，研究了早期职业阶段（博士和博士后）研究主题的时间投入与产出新颖性之间的关系，发现投入时间与新颖性呈倒U型关系，且准备阶段投入有正面影响。
This study explores how scientists navigate research topic transitions during their early-career training and examines its impact on the production of novel knowledge. Drawing on survey data of 270 mid-career scientists in life sciences, we investigate their time investment in topics during early career stages (i.e. during PhD and postdoc training) and trace their research output for 15 years after earning their PhD degree. We find an inverted U-shaped relationship between time investment in the first topic and the novelty of research output. Thus, the learning effect seems to contribute to novelty with diminishing returns, and too long a time investment in a topic results in knowledge saturation and lock-in. This negative effect is long-lasting – too long commitment to a topic decreases the chance of novel discoveries even after they switch to different topics. We also investigate how scientists allocate time across different phases within a topic, finding that time invested in the preparatory phase (identifying and formulating research question, etc.) has a positive effect on novelty, whereas time in the generation phase (producing results, etc.) has a negative effect. Importantly, these effects last for over 10 years after they switch topics. Thus, exploring research topics through trials and errors in the preparatory phase of a topic helps scientists develop domain-unspecific creative skills that benefit different topics throughout their careers. We further analyze time investment in later topics during early-career training and its impact on novel knowledge production.