PP(top x%) is the proportion of papers of a unit (e.g., an institution or a group of researchers), which belongs to the x% most frequently cited papers in the corresponding fields and publication years. It has been proposed that x% of papers can be expected which belongs to the x% most frequently cited papers. In this Brief Communication we will present the results of an empirical test whether we can really have this expectation and how strong the deviations from the expected values are when many random samples are drawn from the database.

中文翻译：

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百分位指标的预期值

PP(top x%)是一个单位（例如，一个机构或一组研究人员）的论文所占的比例，属于相应领域和发表年份中最常被引用的x%的论文。有人提出可以预期 x% 的论文属于 x% 最常被引用的论文。在这个简短的交流中，我们将展示一个经验测试的结果，我们是否真的可以有这个期望，以及当从数据库中抽取许多随机样本时，与期望值的偏差有多大。