Journal classification into subject categories is an important aspect in scholarly research evaluation as well as in bibliometric analysis. Journal classification systems use a variety of (partially) overlapping and non-exhaustive subject categories which results in many journals being classified into more than a single subject category. As such, discrepancies are likely to be encountered within any given system and between different systems. In this study, we set to examine both types of discrepancies in the two most widely used indexing systems - Web Of Science and Scopus. We use known distance measures, as well as logical set theory to examine and compare the category schemes defined by these systems. Our results demonstrate significant discrepancies within each system where a higher number of classified categories correlates with increased range and variance of rankings within them, and where redundant categories are found. Our results also show significant discrepancies between the two system. Specifically, very few categories in one system are "similar" to categories in the second system, where "similarity" is measured by subset & interesting categories and minimally covering categories. Taken jointly, our findings suggest that both types of discrepancies are systematic and cannot be easily disregarded when relying on these subject classification systems.

中文翻译：

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期刊主题分类：Web Of Science 和 Scopus 中的系统内和系统间差异

将期刊分类为学科类别是学术研究评估和文献计量分析的一个重要方面。期刊分类系统使用各种（部分）重叠和非详尽的学科类别，这导致许多期刊被归入多个学科类别。因此，在任何给定系统内和不同系统之间都可能遇到差异。在这项研究中，我们着手检查两个最广泛使用的索引系统 - Web Of Science 和 Scopus 中的两种类型的差异。我们使用已知的距离度量以及逻辑集合论来检查和比较这些系统定义的类别方案。我们的结果表明，每个系统内都存在显着差异，其中更多的分类类别与其中的排名范围和方差增加相关，并且发现了冗余类别。我们的结果还显示了两个系统之间的显着差异。具体来说，一个系统中很少有类别与第二个系统中的类别“相似”，其中“相似性”是通过子集和有趣类别以及最小覆盖类别来衡量的。综合来看，我们的研究结果表明，两种类型的差异都是系统性的，在依赖这些主题分类系统时不能轻易忽视。具体来说，一个系统中很少有类别与第二个系统中的类别“相似”，其中“相似性”是通过子集和有趣类别以及最小覆盖类别来衡量的。综合来看，我们的研究结果表明，两种类型的差异都是系统性的，在依赖这些主题分类系统时不能轻易忽视。具体来说，一个系统中很少有类别与第二个系统中的类别“相似”，其中“相似性”是通过子集和有趣类别以及最小覆盖类别来衡量的。综合来看，我们的研究结果表明，两种类型的差异都是系统性的，在依赖这些主题分类系统时不能轻易忽视。