How Much is the Whole Really More than the Sum of its Parts? 1 + 1 = 2.5: Superlinear Productivity in Collective Group Actions

In a variety of open source software projects, we document a superlinear growth of production ($R \sim c^\beta$) as a function of the number of active developers $c$, with $\beta \simeq 4/3$ with large dispersions. For a typical project in this class, doubling of the group size multiplies typically the output by a factor $2^\beta=2.5$, explaining the title. This superlinear law is found to hold for group sizes ranging from 5 to a few hundred developers. We propose two classes of mechanisms, {\it interaction-based} and {\it large deviation}, along with a cascade model of productive activity, which unifies them. In this common framework, superlinear productivity requires that the involved social groups function at or close to criticality, in the sense of a subtle balance between order and disorder. We report the first empirical test of the renormalization of the exponent of the distribution of the sizes of first generation events into the renormalized exponent of the distribution of clusters resulting from the cascade of triggering over all generation in a critical branching process in the non-meanfield regime. Finally, we document a size effect in the strength and variability of the superlinear effect, with smaller groups exhibiting widely distributed superlinear exponents, some of them characterizing highly productive teams. In contrast, large groups tend to have a smaller superlinearity and less variability.Comment: 29 pages, 8 figure

Empirical research on the evaluation model and method of sustainability of the open source ecosystem

The development of open source brings new thinking and production modes to software engineering and computer science, and establishes a software development method and ecological environment in which groups participate. Regardless of investors, developers, participants, and managers, they are most concerned about whether the Open Source Ecosystem can be sustainable to ensure that the ecosystem they choose will serve users for a long time. Moreover, the most important quality of the software ecosystem is sustainability, and it is also a research area in Symmetry. Therefore, it is significant to assess the sustainability of the Open Source Ecosystem. However, the current measurement of the sustainability of the Open Source Ecosystem lacks universal measurement indicators, as well as a method and a model. Therefore, this paper constructs an Evaluation Indicators System, which consists of three levels: The target level, the guideline level and the evaluation level, and takes openness, stability, activity, and extensibility as measurement indicators. On this basis, a weight calculation method, based on information contribution values and a Sustainability Assessment Model, is proposed. The models and methods are used to analyze the factors affecting the sustainability of Stack Overflow (SO) ecosystem. Through the analysis, we find that every indicator in the SO ecosystem is partaking in different development trends. The development trend of a single indicator does not represent the sustainable development trend of the whole ecosystem. It is necessary to consider all of the indicators to judge that ecosystem’s sustainability. The research on the sustainability of the Open Source Ecosystem is helpful for judging software health, measuring development efficiency and adjusting organizational structure. It also provides a reference for researchers who study the sustainability of software engineering

Influence Of Developer Sentiment And Stack Overflow Developers On Open Source Project Success: An Empirical Examination

The collaborative effort of software developers around the world produces Open Source Software (OSS) products, and most importantly, the source code of the software product is shared publicly. A recent survey of 1300 IT professionals by Black Duck Software showed that the percentage of companies using open source software grew from 42% to 78% between 2010 and 2015. There has been a significant increase in the formation of self-organizing virtual teams to produce open source software products and services. The current literature does not address the factors affecting the success of open source projects through the lens of self-organizing virtual teams and the sentiment among the developers and the sentiment among software developers. This phenomenon suggests a need to understand how successful project teams are created in a virtual collaborative environment. This research investigates how successful virtual teams are formed through the influence of an online developer community. The focus of this research is to assess how the online developer community, Stack Overflow (SO), influences the success of open source projects. More precisely, the study empirically tests the influence of the SO community on successful Github (GH) projects. The investigation also empirically examines how the ties among the software developers in the SO community initiate the self-creation of OSS project teams. The research also explores the perception of the developers about open source projects. Furthermore, the study probes the impact of OSS artifacts, namely “feature” and “patch” requests, on open source projects. The findings indicate that the perception of the developers in the SO community, prior ties among the developers in the community, and the artifact type of the project are the factors that influence the success of OSS projects. The research discusses the implications of the outcomes concerning self-organizing open source project teams

The Allocation of Software Development Resources In ‘Open Source’ Production Mode

This paper aims to develop a stochastic simulation structure capable of describing the decentralized, micro-level decisions that allocate programming resources both within and among open source/free software (OS/FS) projects, and that thereby generate an array of OS/FS system products each of which possesses particular qualitative attributes. The core or behavioral kernel of simulation tool presented here represents the effects of the reputational reward structure of OS/FS communities (as characterized by Raymond 1998) to be the key mechanism governing the probabilistic allocation of agents’ individual contributions among the constituent components of an evolving software system. In this regard, our approach follows the institutional analysis approach associated with studies of academic researchers in “open science” communities. For the purposes of this first step, the focus of the analysis is confined to showing the ways in which the specific norms of the reward system and organizational rules can shape emergent properties of successive releases of code for a given project, such as its range of functions and reliability. The global performance of the OS/FS mode, in matching the functional and other characteristics of the variety of software systems that are produced with the needs of users in various sectors of the economy and polity, obviously, is a matter of considerable importance that will bear upon the long-term viability and growth of this mode of organizing production and distribution. Our larger objective, therefore, is to arrive at a parsimonious characterization of the workings of OS/FS communities engaged across a number of projects, and their collective productive performance in dimensions that are amenable to “social welfare” evaluation. Seeking that goal will pose further new and interesting problems for study, a number of which are identified in the essay’s conclusion. Yet, it is argued that that these too will be found to be tractable within the framework provided by refining and elaborating on the core (“proof of concept”) model that is presented in this paper.