Jonathan L. Krein

Impact of Programming Language Fragmentation on Developer Productivity: A Sourceforge Empirical Study

Programmers often develop software in multiple languages. In an effort to study the effects of programming language fragmentation on productivity-and ultimately on a developers problem-solving abilities-the authors present a metric, language entropy, for characterizing the distribution of a developers programming efforts across multiple programming languages. This paper presents an observational study examining the project contributions of a random sample of 500 SourceForge developers. Using a random coefficients model, the authors find a statistically alpha level of 0.001 and practically significant correlation between language entropy and the size of monthly project contributions. Results indicate that programming language fragmentation is negatively related to the total amount of code contributed by developers within SourceForge, an open source software OSS community.

Design Patterns in Software Maintenance: An Experiment Replication at Brigham Young University

In 2001 Prechelt et al. published the results of a controlled experiment in software maintenance comparing design patterns to simpler solutions. Since that time, only one replication of the experiment has been performed (published in 2004). The replication found remarkably (though not surprisingly) different results. In this paper we present the results of another replication of Prechelts experiment, conducted at Brigham Young University (BYU) in 2010. This replication was performed as part of a joint replication project hosted by the 2011 Workshop on Replication in Empirical Software Engineering Research (RESER). The data and results from this experiment are meant to be considered in connection with the results of other contributions to the joint replication project.

Report from the 1st international workshop on replication in empirical software engineering research (RESER 2010)

The RESER 2010 Workshop, held on May 4, 2010 in Cape Town, South Africa was co-located with the 32nd International Conference on Software Engineering (ICSE 2010). The workshop provided a venue in which empirical Software Engineering researchers could present and discuss the theoretical foundations and methods of replication, as well as the results of specific replicated studies.

Author entropy vs. file size in the gnome suite of applications

We present the results of a study in which author entropy was used to characterize author contributions per file. Our analysis reveals three patterns: banding in the data, uneven distribution of data across bands, and file size dependent distributions within bands. Our results suggest that when two authors contribute to a file, large files are more likely to have a dominant author than smaller files.

The problem of private information in large software organizations

Coordination of project stakeholders is critical to timely and consistent software delivery. In this short paper we present the problem of private information as a guiding framework or lens through which to interpret coordination dynamics within software organizations. We provide evidence of this problem in the form of specific challenges, collected via interviews from a diverse set of extended (i.e., non-development) stakeholders in a globally distributed software development organization.

1st International Workshop on Replication in Empirical Software Engineering Research (RESER)

The RESER 2010 workshop provides a venue in which empirical Software Engineering researchers may present and discuss theoretical foundations and methods of replication, as well as the results of replicated studies.

An open source phylogenetic search and alignment package

PSODA is a comprehensive phylogenetics package, including alignment, phylogenetic search under both parsimony and maximum likelihood, and visualisation and analysis tools. PSODA offers performance comparable to PAUP* in an open source package that aims to provide a foundation for researchers examining new phylogenetic algorithms. A key new feature is PsodaScript, an extension to the nearly ubiquitous NEXUS format, that includes conditional and loop constructs; thereby allowing complex meta-search techniques like the parsimony ratchet to be easily and compactly implemented. PSODA promises to be a valuable tool in the future development of novel phylogenetic techniques. This paper seeks to familiarise researchers with PSODA and its features, in particular the internal scripting language, PsodaScript. PSODA is freely available from the PSODA.

Reflexivity, Raymond, and the success of open source software development: a SourceForge empirical study

Context: Conventional wisdom, inspired in part by Eric Raymond, suggests that open source developers should---and primarily do---develop software for developers like themselves. We refer to the production of software primarily for the benefit of developers as reflexivity, and we evaluate the applicability of this concept to open source software (OSS) by studying SourceForge projects. Objective: The goal of this research is to test Eric Raymonds assertions with respect to OSS success factors. Method: We present four criteria by which to assess project reflexivity in SourceForge. These criteria are based on three specific indicators: intended audiences, relevant topics, and supported operating systems. Results: We show in this short paper that 68% of SourceForge projects are likely reflexive (in the sense described by Raymond). Further, 76% of projects exceeding one million downloads are reflexive, 79% for projects exceeding ten million downloads, and 89% for projects exceeding one hundred million downloads. Conclusion: These results tentatively support Raymonds assertions that 1) OSS projects tend to be reflexive and 2) reflexive OSS projects tend to be more successful than irreflexive projects. Causality, however, is not addressed.

Impact of Communication Structure on System Design: Towards a Controlled Test of Conway's Law

Conways law is generally assumed by researchers and practitioners to hold, despite a relative lack of empirical confirmation. To better understand the effects of Conways law on software development, we conducted a pilot study. The study consisted of a controlled experiment, in which small teams with strictly defined communication channels were tasked with designing a system. We compare the various communication structures of our experimental groups with their resulting system architectures. Due to the small scale of this pilot study, the results are inconclusive. For instance, none of the treatment groups achieved the ideal system architecture, presumably due to Conways law, on the other hand, every treatment groups solution ended up closer to the ideal system architecture than to their organizational structure, which may contradict Conways law. The study also reveals interesting social dynamics that may help explain the law, at least in part. Based on our findings, we hope to replicate this experiment with improved methods and a larger sample size. This report is intended as a contribution to the RESER 2013 joint replication project on Conways law.

An Analysis of Author Contribution Patterns in Eclipse Foundation Project Source Code

Collaborative development is a key tenet of open source software, but if not properly understood and managed, it can become a liability. We examine author contribution data for the newest revision of 251,633 Java source files in 592 Eclipse projects. We use this observational data to analyze collaboration patterns within files, and to explore relationships between file size, author count, and code authorship. We calculate author entropy to characterize the contributions of multiple authors to a given file, with an eye toward understanding the degree of collaboration and the most common interaction patterns.