The increasing ubiquity of digital technology, internet services and social media in our everyday lives allows for a seamless transitioning between the visible and the invisible infrastructure of cities: road systems, building complexes, information and communication technology, and people networks create a buzzing environment that is alive and exciting. Driven by curiosity, initiative and interdisciplinary exchange, the Urban Informatics Research Lab at Queensland University of Technology (QUT), Brisbane, Australia, is an emerging cluster of people interested in research and development at the intersection of people, place and technology with a focus on cities, locative media and mobile technology. This paper seeks to define, for the first time, what we mean by 'urban informatics' and outline its significance as a field of study today. It describes the relevant background and trends in each of the areas of people, place and technology, and highlights the relevance of urban informatics to the concerns and evolving challenges of CSCW. We then position our work in academia juxtaposed with related research concentrations and labels, followed by a discussion of disciplinary influences. The paper concludes with an exposé of the three current research themes of the lab around augmented urban spaces, urban narratives, and environmental sustainability in order to illustrate specific cases and methods, and to draw out distinctions that our affiliation with the Creative Industries Faculty affords.

Mitigating domestic food waste reduces its environmental and economic impacts. In our study, we have identified the use of mobile technology to support behaviour change as a key tool to assist the process of reducing food waste. This paper reports on three mobile applications designed to reduce domestic food waste: Fridge Pal, LeftoverSwap and EatChaFood. The paper examines how each app can influence consumer knowledge of domestic food supply, location, and literacy. We discuss our findings with respect to three considerations: (i) assisting with the user's food supply and location knowledge; (ii) improving the user's food literacy; (iii) facilitating social food sharing of excess food. We present new insights for mobile interventions that encourage changes towards more sustainable behaviours to reduce food waste.

The role and embodiment of the designer/artist in making publics is significant. This special issue draws attention to reflexive practices in Art & Design, and questions how these practices are embedded in the formations and operations of publics, grounded in six cases of participatory design conducted in the United States, India, Turkey, England, Denmark, and Belgium. From these design practices, typologies of participation are formulated that describe the role of the designer. These typologies describe different and sometimes conflicting epistemologies—providing designers with a vocabulary to communicate a diversity of participatory settings and supporting reflexive practices.