Activity theory -- a conceptual framework originally developed by Aleksei Leontiev -- has its roots in the socio-cultural tradition in Russian psychology. The foundational concept of the theory is human activity, which is understood as purposeful, mediated, and transformative interaction between human beings and the world. Since the early 1990s, activity theory has been a visible landmark in the theoretical landscape of Human-Computer Interaction (HCI). Along with some other frameworks, such as distributed cognition and phenomenology, it established itself as a leading post-cognitivist approach in HCI and interaction design. In this book we discuss the conceptual foundations of activity theory and its contribution to HCI research. After making the case for theory in HCI and briefly discussing the contribution of activity theory to the field (Chapter One) we introduce the historical roots, main ideas, and principles of activity theory (Chapter Two). After that we present in-depth analyses of three issues which we consider of special importance to current developments in HCI and interaction design, namely: agency (Chapter Three), experience (Chapter Four), and activity-centric computing (Chapter Five). We conclude the book with reflections on challenges and prospects for further development of activity theory in HCI (Chapter Six). Table of Contents: Introduction: Activity theory and the changing face of HCI / Basic concepts and principles of activity theory / Agency / Activity and experience / Activity-centric computing / Activity theory and the development of HCI

A sociocultural study of workers' ad hoc genre innovations and their significance for information design. In Tracing Genres through Organizations, Clay Spinuzzi examines the everyday improvisations by workers who deal with designed information and shows how understanding this impromptu creation can improve information design. He argues that the traditional user-centered approach to design does not take into consideration the unofficial genres that spring up as workers write notes, jot down ideas, and read aloud from an officially designed text. These often ephemeral innovations in information design are vital components in a genre ecology (the complex of artifacts mediating a given activity). When these innovations are recognized for what they are, they can be traced and their evolution as solutions to recurrent design problems can be studied. Spinuzzi proposes a sociocultural method for studying these improvised innovations that draws on genre theory (which provides the unit of analysis, the genre) and activity theory (which provides a theory of mediation and a way to study the different levels of activity in an organization). After defining terms and describing the method of genre tracing, the book shows the methodology at work in four interrelated studies of traffic workers in Iowa and their use of a database of traffic accidents. These workers developed an ingenious array of ad hoc innovations to make the database better serve their needs. Spinuzzi argues that these inspired improvisations by workers can tell us a great deal about how designed information fails or succeeds in meeting workers' needs. He concludes by considering how the insights reached in studying genre innovation can guide information design itself.

A theory of HCI that uses concepts from semiotics and computer science to focus on the communication between designers and users during interaction. In The Semiotic Engineering of Human-Computer Interaction, Clarisse Sieckenius de Souza proposes an account of HCI that draws on concepts from semiotics and computer science to investigate the relationship between user and designer. Semiotics is the study of signs, and the essence of semiotic engineering is the communication between designers and users at interaction time; designers must somehow be present in the interface to tell users how to use the signs that make up a system or program. This approach, which builds on-but goes further than-the currently dominant user-centered approach, allows designers to communicate their overall vision and therefore helps users understand designs-rather than simply which icon to click. According to de Souza's account, both designers and users are interlocutors in an overall communication process that takes place through an interface of words, graphics, and behavior. Designers must tell users what they mean by the artifact they have created, and users must understand and respond to what they are being told. By coupling semiotic theory and engineering, de Souza's approach to HCI design encompasses the principles, the materials, the processes, and the possibilities for producing meaningful interactive computer system discourse and achieves a broader perspective than cognitive, ethnographic, or ergonomic approaches. De Souza begins with a theoretical overview and detailed exposition of the semiotic engineering account of HCI. She then shows how this approach can be applied specifically to HCI evaluation and design of online help systems, customization and end-user programming, and multiuser applications. Finally, she reflects on the potential and opportunities for research in semiotic engineering.