Context: software projects are common resources in Software Engineering experiments, although these are often selected without following a specific strategy, which reduces the representativeness and replication of the results. An option is the use of preserved collections of software projects, but these must be current, with explicit guidelines that guarantee their updating over a long period of time. Goal: to carry out a systematic secondary study about the strategies to select software projects in empirical studies to discover the guidelines taken into account, the degree of use of project collections, the meta-data extracted and the subsequent statistical analysis conducted. Method: A systematic mapping study to identify studies published from January 2013 to December 2020. Results: 122 studies were identified, of which the 72% used their own guidelines for project selection and the 27% used existent project collections. Likewise, there was no evidence of a standardized framework for the project selection process, nor the application of statistical methods that relates with the sample collection strategy.

中文翻译：

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对软件项目集合进行的实证研究的系统映射研究

背景：软件项目是软件工程实验中的常见资源，尽管这些项目经常在没有遵循特定策略的情况下选择，这降低了结果的代表性和重复性。一种选择是使用保留的软件项目集合，但这些集合必须是最新的，并有明确的指导方针，以保证它们在很长一段时间内的更新。目标：对实证研究中选择软件项目的策略进行系统的二次研究，以发现考虑的指南、项目集合的使用程度、提取的元数据以及随后进行的统计分析。方法：一项系统映射研究，以识别 2013 年 1 月至 2020 年 12 月发表的研究。结果：识别出 122 项研究，其中 72% 使用自己的项目选择指南，27% 使用现有项目集合。同样，没有证据表明项目选择过程的标准化框架，也没有与样本收集策略相关的统计方法的应用。