Due to the ongoing COVID‐19 outbreak, conference virtualization has happened, is happening, and will happen for the recent past, ongoing, and upcoming periods, respectively. An ongoing example of conference virtualization is ICSE 2020, the largest conference in software engineering. ACM has recently formed the ACM Presidential Task Force on What Conferences Can Do to Replace Face‐to‐Face Meetings; in May 2020, this task force released a guide to best practices on virtual conferences (https://www.acm.org/virtual‐conferences). The availability of videoconferencing and/or Webinar systems such as Zoom has made online live presentations of accepted conference papers easy and low cost. One may wonder whether the current technology and platform availability for live presentations can facilitate some innovations of disseminating journal papers, going beyond the current common practice of partnership between journals and conferences, e.g., journal‐first papers. For example, a journal may consider organizing a virtual journal summit every year or every half of a year for authors of accepted or published papers in that journal to present their papers in an online live manner. Indeed, community discussion is needed before these kinds of innovations are put into action. We welcome your thoughts on possible innovations of disseminating journal papers (especially in the face of conference virtualization), and these innovations' potential pros and cons.

This issue contains two papers. In the first paper, Lucas R. Andrade, Patricia D. L. Machado, and Wilkerson. L. Andrade address the problem of predicting the fault detection capability of a test suite. It has previously been observed that although code coverage is often seen as being important, the actual coverage achieved by a test suite is a poor predictor of effectiveness. To address this, recent work has introduced metrics (forms of Operational Coverage) that combine code coverage with information from an operational profile that models the expected usage of the system. This paper reports on the outcomes of a case study that considered 46 versions of a proprietary system. In order to provide an estimate of the effectiveness of a test suite, the authors used the number of post‐release bugs reported (the fewer found, the more effective the test suite). Interestingly, it was found that there was a negative correlation between measures of test suite effectiveness with both versions of statement coverage but that the correlation was stronger with operational statement coverage. (Recommended by Lori L. Pollock).

In the second paper, Yanqiang Liu, Fangge Yan, Mingyuan Xia, Zhengwei Qi, and Xue Liu present TimelyRep, an efficient and deterministic replay tool for web‐enabled mobile applications. TimelyRep achieves deterministic replay of program states and low replay delays in face of the high input rate of mobile interaction. In particular, TimelyRep includes a mechanism for delivering an HTTP response stream with deterministic sequence, contents and latencies, without requiring modification of the browser core or the OS. TimelyRep also includes a mechanism to control replay delays in the JavaScript space, applicable for both the mobile web embeddings and traditional web browsers. This paper reports on an evaluation with two real‐world web game applications with complicated non‐determinism and intensive user inputs. The evaluation results show that TimelyRep is useful for recreating program bugs and maintaining low delays for touch‐intensive web games. (Recommended by Robert Hierons).

由于持续的COVID-19爆发，会议虚拟化已经发生，正在发生，并将分别在最近的过去，正在进行的时期和即将到来的时期发生。会议虚拟化的一个持续示例是ICSE 2020，这是软件工程领域最大的会议。ACM最近成立了ACM总统特别工作组，负责会议可以取代面对面的会议。2020年5月，该工作组发布了虚拟会议最佳实践指南（https://www.acm.org/virtual-conferences）。视频会议和/或网络研讨会系统（如Zoom）的可用性使接受的会议论文的在线实时演示变得容易且成本低廉。有人可能想知道，当前用于现场演示的技术和平台是否可以促进传播期刊论文的一些创新，超越了当前期刊和会议之间的合作伙伴关系的惯例，例如期刊第一篇论文。例如，某期刊可能考虑每年或每半年组织一次虚拟期刊峰会，以供该期刊中被接受或发表的论文的作者以在线实时方式展示其论文。确实，在将这些创新付诸实践之前，需要进行社区讨论。我们欢迎您对传播期刊论文的可能创新（尤其是面对会议虚拟化）的想法，以及这些创新的潜在利弊的想法。期刊可以考虑每年或半年组织一次虚拟期刊峰会，以供该期刊中已接受或发表的论文的作者以在线实时方式展示其论文。确实，在将这些创新付诸实践之前，需要进行社区讨论。我们欢迎您对传播期刊论文的可能创新（尤其是面对会议虚拟化）的想法，以及这些创新的潜在利弊的想法。期刊可以考虑每年或半年组织一次虚拟期刊峰会，以供该期刊中已接受或发表的论文的作者以在线实时方式展示其论文。确实，在将这些创新付诸实践之前，需要进行社区讨论。我们欢迎您对传播期刊论文的可能创新（尤其是面对会议虚拟化）的想法，以及这些创新的潜在利弊的想法。

本期包含两篇论文。在第一篇论文中，Lucas R. Andrade，Patricia DL Machado和Wilkerson。L. Andrade解决了预测测试套件的故障检测能力的问题。以前已经观察到，尽管通常将代码覆盖率视为重要的，但是测试套件所达到的实际覆盖率却不能很好地预测有效性。为了解决这个问题，最近的工作引入了度量（操作覆盖率的形式），该度量将代码覆盖率与来自操作配置文件的信息相结合，该信息对系统的预期使用进行了建模。本文报告了一个案例研究的结果，该案例研究了46个版本的专有系统。为了估算测试套件的有效性，作者使用了报告的发布后错误数量（发现的错误数量越少，测试套件越有效）。有趣的是，发现测试套件有效性的度量与两种版本的语句覆盖率之间都存在负相关，但与操作语句覆盖率之间的相关性更强。（由Lori L. Pollock推荐）。

在第二篇论文中，刘彦强，闫芳阁，夏明远，齐正伟和刘雪介绍了TimelyRep，这是一种用于Web的移动应用程序的高效且确定性的重放工具。面对移动交互的高输入率，TimelyRep实现了程序状态的确定性重播和低重播延迟。特别地，TimelyRep包括一种机制，该机制用于传递具有确定性序列，内容和延迟的HTTP响应流，而无需修改浏览器核心或OS。TimelyRep还包括一种控制JavaScript空间中的重播延迟的机制，适用于移动Web嵌入和传统Web浏览器。本文报告了两个具有复杂的不确定性和大量用户输入的真实世界网络游戏应用程序的评估。评估结果表明，TimelyRep对于重新创建程序错误并保持触摸密集型网络游戏的低延迟很有用。（Robert Hierons推荐）。