Thanks to the Internet and the related availability of “Big Data,” social interactions and their environmental context can now be studied experimentally. In this article, we discuss a methodology that we term the online field experiment to differentiate it from more traditional lab-based experimental designs. We explain how this experimental method can be used to capture theoretically relevant environmental conditions while also maximizing the researcher’s control over the treatment(s) of interest. We argue that this methodology is particularly well suited for social psychology because of its focus on social interactions and the factors that influence the nature and structure of these interactions. We provide one detailed example of an online field experiment used to investigate the impact of the sharing economy on trust behavior. We argue that we are fundamentally living in a new social world in which the Internet mediates a growing number of our social interactions. These highly prevalent forms of social interaction create opportunities for the development of new research designs that allow us to advance our theories of social interaction and social structure with new data sources.

The sharing economy is a new online community that has important implications for offline behavior. This study evaluates whether engagement in the sharing economy is associated with an actor’s aversion to risk. Using a web-based survey and a field experiment, we apply an adaptation of Holt and Laury’s (2002) risk lottery game to a representative sample of sharing economy participants. We find that frequency of activity in the sharing economy predicts risk aversion, but only in interaction with satisfaction. While greater satisfaction with sharing economy websites is associated with a decrease in risk aversion, greater frequency of usage is associated with greater risk aversion. This analysis shows the limitations of a static perspective on how risk attitudes relate to participation in the sharing economy.

New grassroots organizations that target ethical consumer choices and behavior represent a departure from traditional social movement organizations. In this article, we study the activists of one of these organizations and show that social network ties formed mainly online greatly reinforce commitment toward the goals of the movement. We suggest that online ties, that is, digital ties, are important for political consumerism movements because they create audiences for private actions. It is because of the presence of these audiences that the individual participants can reinterpret their actions into public ones. We used an online survey to collect data on the users of the Transition US social website on Ning.com. Over half of the respondents have experiences with political activism. However, their responses indicate that they are dissatisfied with traditional means of political participation (e.g. rallies) and prefer non-contentious collective actions (e.g. local gardening). Respondents perceive community organizing to be the most effective way to bring about social change, deprioritizing connections to local government. Furthermore, respondents who formed digital ties with other activists were significantly more likely than respondents who had no ties with other activists to adopt consumer changes consistent with the goals of the movement. We interpreted this finding as an indicator that digital ties share some of the characteristics of strong ties, and we explored this similarity in this article.

In this paper we explore two contrasting perspectives on individuals' participation in associations. On the one hand, some have considered participation the byproduct of pre-existing friendship ties — the more friends one already has in the association, the more likely he or she is to participate. On the other hand, some have considered participation to be driven by the association's capacity to form new identities — the more new friends one meets in the association, the more likely he or she is to participate. We use detailed temporal data from an online association to adjudicate between these two mechanisms and explore their interplay. Our results show a significant impact of new friendship ties on participation, compared to a negligible impact of pre-existing friends, defined here as ties to other members formed outside of the organization's context. We relate this finding to the sociological literature on participation and we explore its implications in the discussion.

This issue examines the social transformations brought about by novel tools of social interactions. Man builds tools to change the world and in turn, the tools change the man that built them. It is this dynamic process that each of the articles presented here explores. Some common themes emerge across all the contributions:-Emphasis on the Social and Cultural Construction of Data-Driven Domains: Brandt examines the cultural construction of data science through the lens of motives, meaning-making, and disputes on social media. Kaul and Mukherjee focus on the "Equitable Differential Privacy" framework, arguing that ensuring equitable outcomes requires not just algorithmic design but also inclusive communication that considers diverse social groups and power dynamics. Sakamoto et al. analyze how the established practice of offline diplomacy is being augmented and selectively adopted in the online sphere, highlighting strategic and presentational considerations that reflect social norms and diplomatic goals.-Leveraging Computational Methods for Social Inquiry: Each article employs computational social science methodologies to analyze large datasets. Brandt utilizes network analysis and topic modeling on a large corpus of tweets. Kaul and Mukherjee conduct a descriptive case study, drawing on secondary sources related to the U.S. Census Bureau's communication strategies, which implicitly involves analyzing textual data and communication patterns. Sakamoto et al. explicitly use quantitative text analysis tools like word embeddings, topic modeling (LDA), and sentiment analysis on corpora of UN speeches and X posts. •Ethical and Equity Concerns: Two of the articles touch upon ethical and equity considerations within their respective domains. Brandt notes the emergence of concerns with "new practical and ethical standards" in the construction of data science. Kaul and Mukherjee make "equity" the central focus of their work on differential privacy, arguing for a framework that addresses the needs of all social groups, particularly marginalized ones, through both algorithmic design and inclusive communication. •Examining the Role of Online Platforms in Professional and Political Practices: All three articles consider the significance of online platforms in transforming professional and political practices. Brandt uses Twitter to study the cultural construction of data science. Kaul and Mukherjee analyze communication related to the Census Bureau's DP implementation, which includes online dissemination of information. Sakamoto et al. directly compare offline diplomatic speeches with online posts on X, highlighting how diplomats leverage these platforms to complement their traditional roles. A goal of this issue is to promote the circulation of ideas between academia and tech companies by encouraging research on topics that are relevant for both communities. We think that the topics covered in this issue offer a starting point for starting a dialogue between the two communities of researchers. As such, we see this as a beginning, a first step that recognize the existence of a new domain of knowledge that uses social science concepts and ideas for building tools that shape interactions.