There is now a growing body of research on formal algorithmic models of social procedures and interactions between rational agents. These models attempt to identify logical elements within our day-to-day social activities. Largely using the language of logic and game theory, these studies have led to new insights into the dynamics of observation, updating of knowledge and belief, preference change, dialogues and processes of strategic interaction. Central to many of these studies is a

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... t perspective on rational agency that situates inference in an interactive context. Logical studies of the role of communication, information exchange and even information hiding are broadening the scope of research on social interaction. This special issue of Knowledge, Rationality and Action centres on the relation between epistemic attitudes and multi-agent interaction. We have five papers that explore different aspects of this relationship: how awareness determines knowledge and ignorance, how communications can ensure some agents' ignorance while increasing other agents' knowledge, what merging beliefs may mean in strategic terms, and what may be the linguistic desiderata for epistemic communication protocols. They typically employ models based on dynamic and temporal epistemic logics to study these questions. In all of them, one central issue contributes to complexity: intersubjectivity, whereby agents' reasoning about each others' awareness, knowledge and belief, is essential to the design and analysis of their interactions. Agents' knowledge may in general be limited in many ways. One important way is by which they access such knowledge: agents observe events in the external world,