Centre for Science and Technology Studies, Leiden University, Leiden, The Netherlands.
PLoS One. 2013 Apr 24;8(4):e62395. doi: 10.1371/journal.pone.0062395. Print 2013.
Citation analysis has become an important tool for research performance assessment in the medical sciences. However, different areas of medical research may have considerably different citation practices, even within the same medical field. Because of this, it is unclear to what extent citation-based bibliometric indicators allow for valid comparisons between research units active in different areas of medical research.
A visualization methodology is introduced that reveals differences in citation practices between medical research areas. The methodology extracts terms from the titles and abstracts of a large collection of publications and uses these terms to visualize the structure of a medical field and to indicate how research areas within this field differ from each other in their average citation impact.
Visualizations are provided for 32 medical fields, defined based on journal subject categories in the Web of Science database. The analysis focuses on three fields: Cardiac & cardiovascular systems, Clinical neurology, and Surgery. In each of these fields, there turn out to be large differences in citation practices between research areas. Low-impact research areas tend to focus on clinical intervention research, while high-impact research areas are often more oriented on basic and diagnostic research.
Popular bibliometric indicators, such as the h-index and the impact factor, do not correct for differences in citation practices between medical fields. These indicators therefore cannot be used to make accurate between-field comparisons. More sophisticated bibliometric indicators do correct for field differences but still fail to take into account within-field heterogeneity in citation practices. As a consequence, the citation impact of clinical intervention research may be substantially underestimated in comparison with basic and diagnostic research.
引文分析已成为医学科学研究绩效评估的重要工具。然而，即使在同一医学领域内，不同的医学研究领域可能有很大不同的引文习惯。正因为如此，尚不清楚基于引文的文献计量指标在多大程度上允许在不同医学研究领域活跃的研究单位之间进行有效的比较。
介绍了一种可视化方法，该方法揭示了医学研究领域之间引文习惯的差异。该方法从大量出版物的标题和摘要中提取术语，并使用这些术语来可视化医学领域的结构，并表明该领域内的研究领域在其平均引文影响方面彼此有何不同。
提供了 32 个医学领域的可视化，这些领域是基于 Web of Science 数据库中的期刊主题类别定义的。分析集中在三个领域：心脏和心血管系统、临床神经病学和外科学。在这些领域中的每一个领域，研究领域之间的引文习惯都存在很大差异。低影响力的研究领域往往侧重于临床干预研究，而高影响力的研究领域通常更侧重于基础和诊断研究。
流行的文献计量指标，如 h 指数和影响因子，不能纠正医学领域之间引文习惯的差异。因此，这些指标不能用于进行准确的领域间比较。更复杂的文献计量指标确实可以纠正领域差异，但仍未能考虑引文习惯的领域内异质性。因此，与基础和诊断研究相比，临床干预研究的引文影响可能会大大低估。
