Confounders (or confounding variables) pose significant challenges to detecting reliable causal relationships in observational studies. When data are collected from naturally occurring phenomena—e.g., mining software repositories (MSR)—researchers cannot rely on randomization to control for confounders, leading to biased causal inferences. Alternative approaches are required to mitigate confounding bias when exploring causal inferences. This paper explains and exemplifies the use of matching in MSR.

Software quality research increasingly relies on large-scale datasets that measure both the product and process aspects of software systems. However, existing resources often focus on limited dimensions, such as code smells, technical debt, or refactoring activity, thereby restricting comprehensive analyses across isolated quality dimensions. To address this gap, we present the Software Quality Dataset (SQuaD), a multi-dimensional, time-aware collection of software quality metrics extracted from 450 mature open-source projects across diverse ecosystems, including Apache, Mozilla, FFmpeg, and the Linux kernel. By integrating nine state-of-the-art static analysis tools, i.e., SonarQube, CodeScene, PMD, Understand, CK, JaSoMe, RefactoringMiner, RefactoringMiner++, and PyRef, our dataset unifies over 700 unique metrics at method, class, file, and project levels. Covering a total of 63,586 analyzed project releases, SQuaD also provides version control and issue-tracking histories, software vulnerability data (CVE/CWE), and process metrics proven to enhance Just-In-Time (JIT) defect prediction. The SQuaD enables empirical research on maintainability, technical debt, software evolution, and quality assessment at unprecedented scale. We also outline emerging research directions, including automated dataset updates and cross-project quality modeling to support the continuous evolution of software analytics. The dataset is publicly available on ZENODO (DOI: 10.5281/zenodo.17566690).

The rapid diffusion of Large Language Models (LLMs) is fundamentally changing how Mining Software Repositories (MSR) research is conducted, particularly for studies that rely on unstructured textual artifacts such as commit messages, issue discussions, pull request reviews, and practitioner-generated content. While recent work has demonstrated the potential of LLMs to support classification, summarization, and qualitative analysis tasks, the majority of existing approaches rely on interactive or API-based executions [2, 3, 6]. Such execution models are poorly suited for large-scale empirical MSR studies, where thousands or hundreds of thousands of artifacts must be processed in a controlled, reproducible, and cost-aware manner.

Mining Software Repositories studies have become increasingly popular over the years. However, a notable limitation is that they report correlational relationships rather than establishing causation. In contrast, certain disciplines (e.g. epidemiology) have developed specific methods to address this limitation. The goal of this tutorial is to introduce participants to one such method: cohort studies. By the end of the tutorial, participants will be familiar with the steps and techniques involved in designing and analyzing cohort studies.