What's in a GitHub Star? Understanding Repository Starring Practices in a Social Coding Platform (1811.07643v1)

Abstract: Besides a git-based version control system, GitHub integrates several social coding features. Particularly, GitHub users can star a repository, presumably to manifest interest or satisfaction with an open source project. However, the real and practical meaning of starring a project was never the subject of an in-depth and well-founded empirical investigation. Therefore, we provide in this paper a throughout study on the meaning, characteristics, and dynamic growth of GitHub stars. First, by surveying 791 developers, we report that three out of four developers consider the number of stars before using or contributing to a GitHub project. Then, we report a quantitative analysis on the characteristics of the top-5,000 most starred GitHub repositories. We propose four patterns to describe stars growth, which are derived after clustering the time series representing the number of stars of the studied repositories; we also reveal the perception of 115 developers about these growth patterns. To conclude, we provide a list of recommendations to open source project managers (e.g., on the importance of social media promotion) and to GitHub users and Software Engineering researchers (e.g., on the risks faced when selecting projects by GitHub stars).

• The paper finds that 75% of surveyed developers consider star counts crucial when evaluating GitHub projects.
• It employs clustering on the top 5,000 projects to identify four distinct star growth patterns, including a 2.3% viral surge pattern.
• The study highlights that active promotion and regular updates drive star accrual, cautioning against sole reliance on stars as a quality metric.

Understanding GitHub Repository Starring Practices: A Study

The research conducted by Borges and Valente offers a comprehensive examination of the significance, characteristics, and growth dynamics of GitHub stars. This investigation is rooted in empiricism and seeks to elucidate the motivations behind the starring of repositories, a feature integrated into the GitHub platform allowing users to express interest in projects.

Key Findings

The paper begins by surveying 791 developers, revealing that a significant majority, 75%, regard the number of stars as a critical factor when considering whether to use or contribute to a GitHub project. This fact underscores the weight of stars as a metric of popularity and potential quality within the developer community.

Further quantitative analysis was performed on the top 5,000 starred GitHub repositories to identify patterns in star growth. Four distinct growth patterns were identified: Slow, Moderate, Fast, and Viral. These patterns were derived through clustering techniques, yielding insights into the dynamics of open source project visibility and evolution on GitHub. In particular, 58.2% of repositories follow a Slow growth pattern, while Viral growth, marked by a sudden surge in stars, was less common, accounting for just 2.3% of repositories.

An extension of the paper involved two additional surveys. The first, with 791 developers, delved into motivations for starring projects, identifying reasons such as appreciation, bookmarking for future reference, and current usage. The second survey targeted 115 project owners to gauge their perceptions of growth patterns, with findings suggesting that active promotion and usage of trending technologies significantly influence star accrual.

Implications

This work has several notable implications for both open source project managers and software engineering researchers. For practitioners, the paper underscores the importance of active promotion, particularly through social media, to boost project visibility and star counts. Maintaining active and engaging projects through regular updates and community interaction is linked to a higher growth rate in stars.

For researchers, the findings urge caution when using stars as a primary metric for selecting GitHub projects in empirical studies. The potential for selection bias is evident, as reliance on stars may skew results toward well-promoted projects or those benefiting from a sudden surge of interest, rather than reflecting intrinsic software quality or engineering rigor.

Future Directions

The paper proposes several opportunities for ongoing research. A deeper exploration into the characteristics of low-star repositories might offer contrasting insights to further understand the mechanics of project visibility and developer engagement. Additionally, establishing correlations between a repository's stars and the programming language's broader popularity might yield relative measures of project success. Such research could enhance our understanding of what constitutes effective practices for GitHub project management and selection in empirical software engineering studies.

In conclusion, Borges and Valente's paper advances our comprehension of GitHub's starring feature as a metric of project popularity. It provides actionable recommendations for project managers and researchers, urging a meticulous approach to leveraging stars in assessing software projects' potential impact and quality. The open data and tooling support provided by this research further facilitate future explorations and practical applications in software development and research.