Twitlang(er): Interactions Modeling Language (and Interpreter) for Twitter

Online social networks are widespread means to enact interactive collaboration among people by, e.g., planning events, diffusing information, and enabling discussions. Twitter provides one of the most illustrative example of how people can effectively interact without resorting to traditional communication media. For example, the platform has acted as a unique medium for reliable communication in emergency or for organising cooperative mass actions. This use of Twitter in a cooperative, possibly critical, setting calls for a more precise awareness of the dynamics regulating message spreading. To this aim, in this paper, we propose Twitlang, a formal language to model interactions among Twitter accounts. The operational semantics associated to the language allows users to clearly and precisely determine the effects of actions performed by Twitter accounts, such as post, retweet, reply-to or delete tweets. The language is implemented in the form of a Maude interpreter, Twitlanger, which takes a language term as an input and, automatically or interactively, explores the computations arising from the term. By relying on this interpreter, automatic verification of communication properties of Twitter accounts can be carried out via the analysis tools provided by the Maude framework. We illustrate the benefits of our executable formalisation by means of few simple, yet typical, examples of Twitter interactions, whose effects are somehow subtle.