Google Scholar to overshadow them all? Comparing the sizes of 12 academic search engines and bibliographic databases
Google Scholar to overshadow them all? Comparing the sizes of 12 academic search engines and bibliographic databases
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DOI：
10.1007/s11192-018-2958-5
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发表时间：
2019-01-01
期刊：
影响因子：
3.9
通讯作者：
Gusenbauer, Michael
中科院分区：
文献类型：
--
作者：
Gusenbauer, Michael
关于学术搜索引擎和书目数据库的规模的信息往往是过时的或完全不可用的。因此，很难评估特定数据库的范围，如谷歌学者。虽然科学计量学研究以前曾估计过ASEBD的大小，但所采用的方法只能比较几个数据库。因此，没有最新的关于受欢迎的ASE BD大小的比较信息。这项研究旨在通过提供12种最常用的ASE BD的对比图片来填补这一盲点。在这样做的过程中，我们通过统计查询命中数据作为可访问记录数量的指标，在之前的科学计量学研究的基础上进行了改进。迭代查询优化使确定大多数ASEBD的最大命中数成为可能。通过将这些结果与关于数据库大小的官方信息或之前的科学计量学研究进行比较，验证了它们评估数据库大小的能力。这里使用的查询是可复制的，因此可以快速更新大小信息。这些发现首次提供了对ProQuest和EbScothost的规模估计，并表明谷歌学者的规模到目前为止可能被低估了50%以上。据我们估计，拥有3.89亿条记录的谷歌学者是目前最全面的学术搜索引擎。
Information on the size of academic search engines and bibliographic databases (ASEBDs) is often outdated or entirely unavailable. Hence, it is difficult to assess the scope of specific databases, such as Google Scholar. While scientometric studies have estimated ASEBD sizes before, the methods employed were able to compare only a few databases. Consequently, there is no up-to-date comparative information on the sizes of popular ASEBDs. This study aims to fill this blind spot by providing a comparative picture of 12 of the most commonly used ASEBDs. In doing so, we build on and refine previous scientometric research by counting query hit data as an indicator of the number of accessible records. Iterative query optimization makes it possible to identify a maximum number of hits for most ASEBDs. The results were validated in terms of their capacity to assess database size by comparing them with official information on database sizes or previous scientometric studies. The queries used here are replicable, so size information can be updated quickly. The findings provide first-time size estimates of ProQuest and EbscoHost and indicate that Google Scholar's size might have been underestimated so far by more than 50%. By our estimation Google Scholar, with 389 million records, is currently the most comprehensive academic search engine.