XXX-X-XXXX-XXXX-X/XX/$XX.00 ©20XX IEEE Stack Overflow – Informal learning and the global expansion of professional development and opportunities in programming? Markus Nivala Department of Education, Communication and Learning University of Gothenburg Gothenburg, Sweden markus.nivala@gu.se Alena Seredko Department of Education, Communication and Learning University of Gothenburg Gothenburg, Sweden alena.seredko@gu.se Tanya Osborne Department of Education, Communication and Learning University of Gothenburg Gothenburg, Sweden tanya.osborne@gu.se Thomas Hillman Department of Applied Information Technology University of Gothenburg Gothenburg, Sweden thomas.hillman@gu.se Abstract—The purpose of this study is to examine if, and to what extent, online Community Question Answering platforms expand the opportunities for professional development in programming. Longitudinal and cross-sectional analyses of Stack Overflow Developer Surveys were used to examine users’ geographical distribution, gender, experience, professional status, platform usage and education. In order to study differences between the countries with the largest number of respondents, the developer survey data was combined with indicators of human development, gender equality and educational attainment. The results show that the Stack Overflow community has expanded to some extent, both in terms of wider geographical distribution and the programming expertise of users. However, the community reflects and fails to mitigate the apparent gender disparity in the field of programming. Furthermore, participation seems to be conditioned by formal education, especially in developing countries. In general, participation patterns in Stack Overflow seem to be heavily influenced by local conditions in different countries. Keywords—informal learning, programming, stack overflow, equality I. INTRODUCTION Informal lifelong learning through networked online communities and the timely issue of fostering programming skills across the population represent key parts of the information communication technology (ICT) literacy aspect of 21st Century Skills [1] and policy initiatives at national and transnational levels [2]. The purpose of this study is to examine if and to what extent a particular type of online community, Community Question Answering (CQA) platforms, expand the opportunities for expertise development in programming using Stack Overflow as a case. In particular, the aim is to study how users with different backgrounds are represented in the community and to discuss the possible obstacles for participation in informal learning of programming. Expertise in programming, and its development, has traditionally been studied at the individual level by, for example, comparing novices to experts in terms of their knowledge and reasoning strategies [3-5]. In the last decade, however, “additional emphasis has been placed on the idea of considering learning as an interactive process of ongoing participation in various cultural practices and in shared learning activities” [6, p. 176]. Indeed, studies have shown that programming expertise is connected to better communication and cooperation skills as well as to the presence of highly functional personal networks [4]. Studying expertise development in its social context is especially pertinent to programming. Large-scale software development projects are often (multinational) collaborations between largely autonomous teams that are engaged in joint problem-solving processes [7]. Furthermore, the online platforms that support such collaboration are becoming more and more important as resources for expertise development [8], meaning that programming expertise increasingly resides and develops in networked communities. Stack Overflow is a popular online community where more than 50 million “professional and aspiring programmers visit Stack Overflow each month to help solve coding problems, develop new skills, and find job opportunities" [9]. Unlike most discussion forums, Stack Overflow is structured as a CQA platform for professional and enthusiast programmers that is focused on finding solutions to authentic programming problems. This follows the model of earlier non-programming focused CQA platforms like ProfNet, WikiAnswers and Yahoo! Answers with a cross pollination of features between platforms, leading to a distinct structure that differentiates CQA from other types of knowledge sharing platforms. As is the case with most current CQA, the Stack Overflow community and its content is moderated by users and organised based on user assigned subject area tags. The quality and relevance of content is moderated by voting questions and answers up or down in a process that affects their visibility to the community. Votes that members receive for posed questions or given answers in turn determine the members’ ‘reputation score’. The higher the reputation, the more privileges a member has access to (e.g. acquiring status as a community moderator). Furthermore, it has been argued that participation in the community, as indicated by reputation score, enables users to obtain recognition and social prestige among their peers [10, 11], and to develop their identities as experts in the community [12]. Moreover, the reputation score may serve as a way to demonstrate expertise when applying for a job [13]. Therefore, Stack Overflow can be seen as a potential platform for professional development and opportunities. However, past research has shown that there are considerable barriers to participation and engagement. For example, Oliviera, Andrade and Reinecke [14] studied Stack Overflow participation patterns in terms of posing questions, providing answers, commenting on posts and editing content. The results show that, compared to users from Eastern countries, users from Western countries are more likely to The Swedish Research Council