0. Preamble This talk is about sustainability and human-computer interaction, or HCI. It is about the future of sustainability research in HCI, or "sustainable HCI". It is intended as a contribution to the ongoing conversation about what we have learned so far in sustainable HCI, what we are trying to do, and what we might do next. The talk is called "reaching out", because my main message is that to be relevant and effective, future sustainable HCI research needs to reach out in three directions. First, we need to reach out to the natural and social sciences. Second, we need to reach out to practitioners in government, industry, civil society, and social movements. And third, we need to reach out to users and involve them more directly in the design, operation, maintenance, and evolution of the systems we build. The talk has three parts. [Slide: Three parts.] First, as we have an interdisciplinary group in this room, I will briefly introduce sustainability, HCI, and sustainable HCI. Second, I will describe the discussion and outcomes from this year's sustainability workshop at CHI, the big HCI conference. I was lead organizer of the workshop. In the workshop, we tried to assess what we have learned collectively in sustainable HCI and chart a way toward more engaged, effective research. We articulated a practical consensus, but avoided deep theoretical questions that will need to be addressed if sustainable HCI's new direction is to have a firm foundation. So in the third part of the talk I will draw on some literature outside HCI, including sustainability science, to sketch possible answers to some of these questions. [Slide: 1. Sustainability, HCI, sustainable HCI] "Sustainability" is a term with broad usage. But discourses on sustainability tend to be concerned with maintaining or improving human quality of life and ecological health in the face of environmental change, especially human-made environmental change. Here are some examples of these changes. [Slide: climate change ("climate disruption"); sea level rise; degradation of ecosystems and their services; biodiversity loss ("sixth mass extinction"); loss of arable land; freshwater and food scarcity; deforestation; desertification; ocean acidification; peaking oil production; rising energy costs.] The details, origins, and implications of these changes, as well as possible social responses, have been discussed by researchers and practitioners in many discourses. [Slide: geography; ecology; climate science; earth systems science; global environmental change research; environmental psychology; ecological economics; social ecology; environmental policy; ecosystem management; social-ecological systems; coupled human-natural systems.] Since about 1999, some of these researchers have gathered under the label "sustainability science". One sustainability science researcher, Robert Kates, describes sustainability science as similar to the health and agricultural sciences in three ways. First, it is use-inspired. That is, it is motivated by practical human problems. Second, it includes both basic and applied research. And third, it aims to put knowledge into action. Here is are some of the practical challenges sustainability science researchers have discussed. [Slide: stabilize population numbers; improve health; provide water and sanitation; intensify agriculture and food security; modify consumption; create sustainable cities; maintain biodiversity; clean air and water; restore marine resources; increase resilience to disaster; reduce poverty in Africa; slow climate change; limit war, conflict, crime, and corruption.] These are of course huge challenges with significant unsolved practical and theoretical questions. HCI researchers have been producing work motivated loosely by these concerns since around 2005, and in earnest since 2007. In a review published in 2010, Carl DiSalvo, Phoebe Sengers, and Hrönn Brynjarsdóttir found 157 papers in the subfield of "sustainable HCI", most published between 2007 and 2009. Despite this growth, many researchers in the subfield seem to agree that sustainable HCI has had little practical or intellectual impact on the big sustainability challenges. They appear also to agree that current approaches seem to hold little promise of doing so. This is slightly disappointing, considering how many researcher-hours and dollars have been spent on this work. But it makes sense if we consider the history of HCI. [Slide: The computer reaches out, Grudin. Include credit.] HCI emerged in the 1970s and 80s as an interdisciplinary field concerned with practical problems of use in complex technological systems. Indeed the full name of the CHI conference, the field's largest and most prestigious publication venue, remains, after 33 years, the "Conference on Human Factors in Computing Systems". It is organized by the equally quaintly-named "Association for Computing Machinery". Paradigmatic problems in early "human factors" work included reducing pilot error in aircraft cockpits and improving task efficiency in interactions between one person and one computer in a work setting. Over time, the field's scope grew to include the social questions raised by technological change in organizations. Researchers especially committed to these questions formed the overlapping field of computer supported cooperative work, or CSCW. In the 1980s and 1990s the social "value proposition" of HCI "proper" seems to have shifted to expanding access to computing by improving its usability. Despite some theoretical struggles, HCI researchers followed early developments such as the mouse and the graphical user interface with a wide range of devices, interaction paradigms, and design techniques that are now widely known. Some -- for example the desktop metaphor, interactive displays, the smartphone, and usability guidelines for desktop software, the web, and mobile phones -- are so ubiquitous that they have become taken for granted. By the mid 2000s the effort to expand access to computing by improving its usability had largely succeeded. [Slide: "we are HCI" #1.] These banners are from the 2010 CHI conference website. As computing technology migrated out of the workplace and into users' homes and everyday lives, the "second wave" of HCI research, focused on work and usability, was succeeded by a "third wave". The third wave expanded the physical and social scope of analysis and design of computing systems beyond the workplace. It also expanded the ontological scope of analysis and design beyond the rational, cognitive, and organizational into the aesthetic, emotional, and cultural. This occasioned new theories and methods, and the elaboration and refinement of theories and methods developed in the second wave. Both second and third wave frameworks came largely from the social and cognitive sciences. The big ones were distributed cognition, phenomenology, and activity theory. [Slide: book covers, with dates and "waves".] By the late 2000s, some HCI researchers had begun to examine some of the unexpected, and perhaps unfortunate, consequences of the spread of computing. [Slide: smartphone use.] Sustainable HCI is a loosely linked set of threads that itself sits loosely within the "third wave" of HCI research. [Slide: "we are HCI" #2.] Sustainable HCI research began in earnest in 2007 with one paper, "Sustainable interaction design", by Eli Blevis. Drawing on an eclectic theory base, Blevis elaborated a new approach to interaction design that would focus on its "material effects" -- specifically, its effects on the environment and people's behavior. He called on HCI researchers and interaction designers to reflect on their roles in producing unsustainability -- for example through computing industry practices such as planned obsolescence. He offered values, methods, and design principles for guiding that reflection. This new approach, sustainable interaction design, aimed to promote a variety of goals, most of which were familiar or at least logical to anyone acquainted with popular sustainability discourse. [Slide: [more attention to] disposal; salvage; recycling; remanufacturing for reuse; reuse as is; achieving longevity of use; sharing for maximal use; achieving heirloom status; finding wholesome alternatives to use; active repair of misuse; linking invention and disposal; promoting renewal and reuse; promoting quality and equality; de-coupling ownership and identity; using natural models and reflection.] Blevis' paper, along with the first sustainability workshop at CHI, held the same year, opened the floodgates. In their review of sustainable HCI three years later, Carl DiSalvo, Phoebe Sengers, and Hrönn Brynjarsdóttir found five loosely connected but distinct genres within the subfield. [Slide: persuasive technology, ambient awareness, sustainable interaction design, formative user studies, pervasive and participatory sensing.] They described persuasive technology as using technology to try to get people behave more sustainably. In this strand, what counts as sustainable behavior is determined by the designers, usually without reference to sustainability research. Sustainability goals in persuasive technology are usually straightforward and measurable, such as reducing electricity or water use or taking public transit instead of driving. In an earlier, non-archival review of sustainable HCI, Elizabeth Goodman described persuasive sustainability research as attending to the user as a consumer with "leisure and power to choose within a free market of possessions, services, and ideals". She observed, with I think some criticism implied, that it tended to ignore questions of poverty, power, ideology, and politics. Ambient awareness, overlapping with persuasive technology, unobtrusively visualizes resource consumption. This work may not aim explicitly to change user behavior. It tends to explore the aesthetic qualities of resource consumption visualization through design prototypes. Persuasive technology and ambient awareness both brought established HCI approaches to sustainability as a new application domain. DiSalvo, Sengers, and Brynjarsdóttir described sustainable interaction design -- work adopting the framing presented by Blevis -- as drawing from the design literature, and as taking a critical and sometimes even philosophical orientation to the question of HCI's role in environmental issues. Unlike persuasive technology and ambient awareness, sustainable interaction design work produced few concrete designs. Rather, it was concerned with designers' approaches to sustainability and to designing. Formative user studies, in contrast, aimed to understand how users understood sustainability. And pervasive and participatory sensing used sensors, sometimes in a "citizen science" or activist mode, to gather data on environmental phenomena such as air quality and make that data publicly accessible and comprehensible, often using information visualization techniques. DiSalvo, Sengers, and Brynjarsdóttir found significant and apparently unintentional redundancy, both between the genres and between sustainable HCI and computer engineering. They also found significant but largely unexamined differences between the genres in assumptions, methods, and outputs. Connections to sustainability research outside HCI were ad hoc, and tended to reflect researchers' own disciplinary backgrounds. There were few connections to professional design. And they did not even mention sustainability practice outside HCI, for example in government, industry, civil society, or social movements. The implication, put shortly, was that sustainable HCI was intellectually incoherent and isolated from real sustainability research. The paper was highly publicized: it received a Best Paper Award and invited panel discussion and was posted to subsequent versions of the official conference website as recommended reading for authors intending to submit papers addressing sustainability. I had been exposed to concepts about sustainability through discourses on sustainable development and ecological economics. What first struck me about sustainability research in HCI was how it seemed to take for granted the material infrastructure of our "information society" -- mass industrial production, fossil fuels, data centers, and so on -- without considering its environmental consequences or its viability in a context shaped by natural systems' finite ability to provide raw materials and absorb wastes. The next few years saw the development of new and generative concepts and themes within sustainable HCI, some of which I contributed to. [Slide: “everyday practice” and practice theory; “the implication not to design”; “undesigning”; non-use; new energy systems (e.g., smart grid); design fictions; calls to activism; design for large-scale social collapse; poverty and other economic constraints; rebound effects; more user and non-user studies (e.g., farmers, “simple living” families).] But with the exception of intensifying critiques of persuasive design, we did little to explicitly address the conceptual inconsistencies identified by DiSalvo, Sengers, and Brynjarsdóttir. And with the exception of a group at IBM Research working on resource consumption information portals in collaboration with municipal utilities in Dubuque, Iowa, it seemed that nobody in the subfield had built anything for anyone to use on an ongoing basis. In this context, a collection of long-running contributors to the subfield proposed a workshop, to be held at CHI 2014, to take stock. [Slide: 2. What have we learned in sustainable HCI?] I ended up being the lead organizer. I managed to convince the other organizers to call the workshop simply "What have we learned?" In our proposal, we said we would -- [Slide: "grapple seriously with the community's unresolved differences; find concrete ways to support work that builds on existing sustainability knowledge within and beyond HCI; and find concrete ways for HCI to contribute to achieving sustainability."] -- "grapple seriously with the community's unresolved differences; find concrete ways to support work that builds on existing sustainability knowledge within and beyond HCI; and find concrete ways for HCI to contribute to achieving sustainability." We said we would produce two documents: a collective statement on the state of the subfield and a set of guidelines and questions to help orient and evaluate future work. We proposed to orient discussion around eight questions. Four were theoretical -- [Slide: 1. What is sustainability? 2. What do we know, from within and beyond HCI, about how sustainability might be achieved? 3. What crucial open questions remain? 4. How can HCI research help achieve sustainability?] -- and four were practical. [Slide: 5. How should HCI & Sustainability research be evaluated (e.g., is it possible or desirable to review papers in different genres with one coherent framework)? 6. How can the community use critiques of past work to develop new, more productive approaches? 7. How can we make better use of sustainability knowledge from outside HCI? 8. How can we encourage work that contributes substantively to practical efforts to achieve sustainability?] The workshop was held on April 27 in Toronto. By August, eight of the 23 participants had co-authored a 2200-word article for a broad HCI readership explaining what we had agreed about. The remaining participants added their names to the document as "signatories", as did two other members of the sustainable HCI research community who did not attend. It came out in Interactions, the Association for Computing Machinery's magazine for HCI researchers and professional interaction designers, in mid-September. [Slide: Interactions article.] In case you can't see it, this was the epigraph we chose for the article. [Slide: "We want to change things for *real*."] The report had four sections: lessons, next steps, practical challenges, and emerging issues. The last two sections were abridged vigorously for publication. We summarized the lessons with these two sentences. [Slide: The issues indexed by the term sustainability pose severe challenges to existing HCI theories, methods, and institutional processes. HCI "business as usual" is not well positioned the contribute substantively to efforts to address the challenges of sustainability.] About the second sentence, Eric Baumer, who was not able to attend the workshop but joined us after to discuss (and offered good comments on the article draft), wrote: "This is an even more challenging and contentious claim than you made in the previous sentence!" That so many researchers agreed to associate their names with these contentious claims I can only see as a sign of at least marginal success. In any case, here are the six lessons. [Slide: "Refraining from articulating clear sustainability aims and metrics impedes assessment of our efficacy in contributing to sustainability."] If we are going to succeed, we need to have a clearer idea of what we are trying to do. [Slide: "The processes that give rise to the issues indexed by the term 'sustainability' are larger in time, space, organizational scale, ontological diversity, and complexity than the scales and scopes addressed by traditional HCI design, evaluation, and fieldwork methods."] This is bigger and more complicated than anything we have done before. [Slide: "Most sustainability-oriented work takes place outside HCI."] We have a lot of reading, listening, and learning to do. [Slide: "There is a great deal of research and practice outside and within HCI that does not explicitly address sustainability, but is relevant to sustainable HCI."] This is so much bigger and more complicated than we knew, we've been doing related work we didn't even know was related. [Slide: "There is a tension between the historical focus on technological novelty in HCI and sustainability goals."] We need to stop with the gadgets. [Slide: "Thus far, sustainable HCI research has had little impact outside HCI."] This one needs no translation. There were also six "next steps", but they can be summarized more shortly. [Slide: Have clear goals and use them to evaluate; consider longer time scales; read outside HCI; build systems people actually use; move beyond consumer resource use to address larger scales and more topics; get beyond simple models and face complexity.] We identified four practical challenges to doing all this. [Slide: Collaboration is hard, especially across fields; the one-year publication cycle in computing rewards short-term projects; the blind, one-step review process in the CHI conference limits dialogue and learning and disincentivizes risk-taking; getting support for socially engaged research from gadget-focused institutions, which are common in computing, is hard.] We also said we would organize an informal submission pre-review process to support dialogue and learning and also start an online sustainability knowledge base to help researchers read more widely. These projects are still being organized. We also identified four more fundamental issues that we think will become more visible in the long term. [Slide: The tension between sustainability and the aim of economic growth that supports and orients, if implicitly, the industry of which HCI is part. The tension between the need to read broadly, think deeply, and collaborate widely and the need to act quickly. The tension between respecting the values of users and preventing users from acting on values whose enactment harms others. The relationship between technology and sustainable social change.] We can talk about these later if you like. [Slide: blank.] I'm happy to have participated in this. We're going to have to fill this agenda in, publicly, with details relevant to specific contexts and sustainability challenges; visions of new information practices and specifications for new systems; and, eventually, accounts of the design, use, maintenance, evolution, and effects of those systems in context. But I think this is a good step toward encouraging sustainable HCI research that is more engaged in two ways. First, work following our suggestions will be more informed by the relevant research in the natural and social sciences. Second, work following our suggestions will be more engaged in and relevant to the practical lives of users who live with both the demands of life in contemporary technological society and the knowledge, increasingly difficult to avoid, of the costs of that way of life. So that's good. But what we didn't do at the workshop is answer the first four questions. [Slide: 1. What is sustainability? 2. What do we know, from within and beyond HCI, about how sustainability might be achieved? 3. What crucial open questions remain? 4. How can HCI research help achieve sustainability?] In fact, in the article we wrote this. [Slide: In response to the first four questions, most of the 23 participants rejected the idea that we could devise a single interpretation of sustainability or orient and evaluate all future sustainable HCI research.] Put this way, it sounds reasonable. But in fact in the workshop we simply agreed not to talk about what we individually meant by sustainability, how we thought it might be achieved, or what HCI's role might be. Perhaps we assumed we would disagree, and so tacitly agreed to disagree, and proceed to more practical questions. I think this was the right move in the workshop, because engaging these questions seriously sometimes leads to ideological debates. It can be extremely difficult to distill a working consensus from such debates. But if we avoid discussing these questions as a community, we are pushing them back to individual researchers, whether we intend to or not. This means that the arguments about what is relevant to "sustainability", what appropriate goals and evaluation methods might be, and what HCI-appropriate approaches are likely to be fruitful, will be had between paper reviewers and authors, between the members of proposal review committees in funding agencies, and between graduate students and their advisors. These conversations will be ad hoc. They will happen in private and often after a significant amount of work is done. And many of them will involve the person or people arguing for a new, untried, potentially professionally risky approach -- our approach -- in trying to convince someone in a position of power over their careers. I don't think this is a likely recipe for change. I think it would be better to have this conversation publicly. And I would like to eventually offer people in such situations some peer-reviewed literature to help them out. I am happy to report that there appears to be some agreement among the organizers of next year's workshop that this is in fact an important next step. The workshop will be in Korea and I am not planning to attend, but I will do what I can to contribute. In my last ten minutes here I will sketch one possible approach to these questions. I will focus on these three. [Slide: What is sustainability? What do we know about how sustainability might be achieved? How can HCI research help achieve sustainability?] Let's start. [Slide: Reaching out] [Slide: What is sustainability?] I want to start with two definitions. The first is abstract and generic in that it can be applied to any "system". The second is concrete and concerns the meaning of the term sustainability as applied to human civilization at a global scale. In the first definition, from the systems theory literature, a system is sustainable if it persists. [Slide: "A sustainable system is one which survives or persists."] This definition is nice in that it is simple. But it has some non-obvious constraints and implications. [Slide: "But there are three complicating questions..."] This is how Costanza and Patten talk about them. I would describe these like this. First, this definition only makes sense if a particular period of time is specified. One must also draw the boundaries of the system clearly. Beyond the system lies the "environment". The state of the system at the end of the period of time in question -- persistence or collapse, survival or death -- is a product of the relation between the system and its environment. This definition is non-normative: a system with effects we don't like may be sustainable. It is also descriptive rather than prescriptive: even if a system with effects we like is unsustainable over a relevant period of time, the assessment or prediction of unsustainability alone does not tell us whether we should allocate resources to make the system sustainable, because those resources need to be taken from somewhere else, which is outside the scope of analysis. So this definition can be useful -- if we know what we want to sustain. But this is a question about values, a political question, and exactly the question we avoided in the workshop, perhaps wisely. Conveniently however, in the international sustainable development literature, there has been decades of discssion about what "sustainability" might mean at the global level. Here is one position. [Slide: the primary goals of a transition toward sustainability over the next two generations should be to meet the needs of a much larger but stabilizing [global] human population, to sustain the life support systems of the planet, and to substantially reduce hunger and poverty.] Using goals outlined in international conventions, the study authors defined these goals like this. [Slide: meet human needs: provide food and nutrition, nurture children, find shelter, provide education, find employment; sustain the life support systems of the planet: ensure the quality and supply of fresh water, control emissions into the atmosphere, protect the oceans, maintain species and ecosystems; substantially reduce hunger and poverty: ensure income growth, provide employment opportunities, maintain essential safety net services.] There is still a lot to clarify here. And you might disagree with even this much, but that's good, because it means we have something to talk about and we won't be writing -- and designing -- past, or even against, each other, without knowing it. But as a thought experiment, let's adopt this interpretation of sustainability for the next few minutes and see where it takes us. One thing that needs to be clarified if we adopt this view is how this is all going to get done. These are not things that are done once and for all. Rather, they are ongoing achievements of whole human systems -- institutions and infrastructures. Two of the central insights of sustainability discourse are relevant to these goals. The first insight is that the ways in which human institutions and infrastructures have met human needs and reduced hunger and poverty so far are eroding the life support systems of the planet. Even from a purely human-centered perspective, this cannot go on, because the life support systems of the planet provide crucial inputs and preconditions for those institutions and infrastructures. The second insight is that institutions and infrastructures have allocated effort unevenly between the goals of meeting human needs and reducing hunger and poverty. More effort goes into meeting the needs and wants of the financially and politically privileged than into reducing hunger and poverty. Indeed it may be that more effort goes into creating more needs among the financially and politically privileged, so that they can be fulfilled, than into reducing hunger and poverty among the poor and politically marginalized. All three goals, then, will be achieved -- that is, sustainability will be achieved, if it is achieved -- by changing institutions and infrastructures so that they meet human needs, sustain the life support systems of the planet, and reduce hunger and poverty on an ongoing basis. In my view, and I think in the view of many contributors to a wide range of sustainability discourses, institutions and infrastructures should be changed to redirect effort from the construction and fulfillment of new desires among the financially and politically privileged toward meeting the needs of the poor and politically marginalized and toward the other two goals. This is a partial answer to the second question. [Slide: How might sustainability be achieved? By changing institutions and infrastructures.] But it raises a further question. [Slide: How are institutions and infrastructures changed?] But -- [Slide: What are institutions and infrastructures?] To answer these questions I will draw on social science research. [Slide: Institutions are the prescriptions that humans use to organize all forms of repetitive and structured interactions including those within families, neighborhoods, markets, firms, sports leagues, churches, private associations, and governments at all scales. (Ostrom 2005, p. 3)] Some more details and examples: [Slide: Individuals interacting within rule-structured situations face choices regarding the actions and strategies they take, leading to consequences for themselves and for others. The opportunities and constraints individuals face in any particular situation, the information they obtain, the benefits they obtain or are excluded from, and how they reason about the situation are all affected by the rules or absence of rules that structure the situation. Further, the rules affecting one situation are themselves crafted by individuals interacting in deeper-level situations. For example, the rules we use when driving to work every day were themselves crafted by officials acting within the collective-choice rules used to structure their deliberations and decisions. (Ostrom 2005, p. 3)] And -- [Slide: People commonly envision infrastructure as a system of substrates -- railroad lines, pipes and plumbing, electrical power plants, and wires. It is by definition invisible, part of the background for other kinds of work. (Star 1999, p. 380)] In the literature on economics and law -- [Slide: “Infrastructure” generally conjures up the notion of a large-scale physical resource made by humans for public consumption. Standard definitions of infrastructure refer to the “underlying framework or foundation of a system”. Familiar examples of of “traditional infrastructure” include (1) transportation systems, such as highway systems, railway systems, airline systems, and ports; (2) communication systems, such as telephone networks and postal services; (3) governance systems, such as court systems; and (4) basic public services and facilities, such as schools, sewers, and water systems.] [Slide: "Infrastructure resources are shared means to many ends. Infrastructure resources may be used as inputs into a wide range of productive processes. Infrastructures generate significant positive spillovers (externalities) that result in large social gains."] And this is also important: [Slide: For a railroad engineer, the rails are not infrastructure but topic. For the person in a wheelchair, the stairs and doorjamb in front of a building are not seamless subtenders of use, but barriers. One person's infrastructure is another's topic, or difficulty. Infrastructure is a fundamentally relational concept, becoming real infrastructure in relation to organized practices. The cook considers the water system as working infrastructure integral to making dinner. For the city planner or the plumber, it is a variable in a complex planning process or a target for repair. (Star 1999, p. 380)] I found it interesting that Ostrom and Star gave similar examples. Ostrom talks about how the rules of the road are shaped by officials working within decision-making rules. And Star talks about the water system, which for the cook is an input into a productive process but for the city planner is problem, variable, or output. I think this is a hint about the relation between these two categories, institutions and infrastructures. In fact, I think they are two views on the same thing, which we could call institution-infrastructure systems. The term "institution" foregrounds the social and organizational aspects of these systems. And the term "infrastructure" foregrounds the physical aspects. Many technical infrastructures are actively operated by organized people following rules -- that is, by institutions. And most institutions have infrastructures associated with them -- for example, the buildings, parking lots, pedestrian paths, vehicle fleets, and maintenance tools that allow a university or corporation to get on with its business. The intangible and often invisible social parts of an institution-infrastructure system -- the "institution" -- and the visible, physical parts -- the "infrastructure" -- are interlinked with one another in complex but very specific ways. This complex but particularly organized collection of interlinkages constitutes the institution-infrastructure system as a whole. And like the abstract systems discussed by Costanza and Patten, most institution-infrastructure systems are also situated within larger systems of the same kind. Sometimes this interconnection is hierarchical but in general it is complex. In any analysis we draw a boundary between the "system" -- the object of study or intervention -- and the "environment", which is taken as given and sketched only in terms of elements that influence the "system". And importantly for our purposes here, part of the environment of any institution-infrastructure system is ecological or biophysical, although a system may be insulated from changes in its ecological context by several layers of other institutions and infrastructure. So we have sketched an answer to this question. [Slide: What are institutions and infrastructures?] What about this one? [Slide: How do institutions and infrastructures change?] The literature on institutions offers a hierarchical view of the formal rules that shape action in institutional settings. In this view, day-to-day actions are shaped by "operational rules". Operational rules are changed by authorized actors in collective-choice situations, governed by collective choice rules. And collective-choice rules are changed by authorized actors in constitutional situations. [Slide: Diagram of situations from Ostrom 2005.] The literature on institutions also discusses informal rules, rules-in-use, and complex configurations of rules interlinked across institutional settings and social-ecological systems, so we really do have a sophisticated theoretical framework available to us here. Susan Leigh Star's empirically formed writing on infrastructure emphasizes the complexity and interconnectedness of infrastructure, and hence the difficulty of change in institution-infrastructure systems. She argues that infrastructure changes incrementally, and that such change is never directed unilaterally from above. "Nobody is really in charge of infrastructure", she writes. While long-term, closely coordinated corporate and governmental efforts do play significant and sometimes even decisive roles in shaping infrastructure, the authority and practical ability to rework large-scale infrastructures to a particular plan rarely inheres in one individual, group, or organization. Even when this does happen, this power is accumulated over time through strategic and opportunistic alliances. In any case, the literatures on institutions and infrastructures suggest that they change from within mainly by the actions of authorized actors in particular social locations, at particular moments. Such changes can be encouraged, forced, or justified by changes in their environment, which is made up at least partly of other institution-infrastructure systems and is therefore partly under the influence of "outside" human actors. The idea of "inside" and "outside" pathways to change in institution-infrastructure systems supports the claim, made in the article published by the workshop participants, that to contribute substantively to practical efforts to achieve sustainability, HCI researchers must work more closely both with users and with practitioners in government, industry, civil society, and social movements. One use of theory is to offer reasoning for (or against) arguments like this. In this case, the reasoning for the foregoing argument in terms of the concepts I have just briefly discussed is that practitioners are situated in particular locations in institution-infrastructure systems. Both their abilities and constraints as actors with specific locations in specific systems, combined with the expanded possibilities for institutional and infrastructural action afforded by computer information systems, may yield fruitful possibilities for interventions in support of system change toward sustainability. So a partial answer to this question -- [Slide: What is the role of HCI in achieving sustainability?] -- which we can now change to this question -- [Slide: What is the role of HCI in enabling and supporting changes in institution-infrastructure systems to allocate more resources toward meeting human needs, sustaining the life support systems of the planet, and reducing hunger and poverty?] -- is that HCI researchers should work with actors in particular locations with respect to particular institution-infrastructure systems -- either strategically inside or outside them -- to create situations that induce the systems to change. This can be done either by "following the rules" or by intentionally working outside them. This is not the whole answer. A main goal of any institution is to coordinate collective action by facilitating and routinizing communication and information exchange, and HCI researchers are specialists in computer information systems, which serve this activity particularly well. So to add to the previous answer, one way we can concretely support institutional change toward sustainability is by ensuring that when the computer information systems that move information around in institutions are designed, deployed, operated, maintained, and evolved, they do so in ways that support the efforts of institutional actors to allocate more resources toward sustainability goals. In the terms of the institutional literature, the design of a new computer information system in an institution is a collective choice situation, and as such it is to some extent an opportunity to reconfigure the institution's operational rules. We should also note that in our globally networked society, some institutions are constituted entirely through software, with members coming to know their roles and the relevant rules through their interactions with and through software interfaces. In these virtual institutions, roles and rules are often encoded and enforced through database architecture and application code. The design of new institutions through software -- especially institutions that will allocate more of members' efforts toward sustainability goals -- is therefore an area of potential significance for sustainable HCI. Such institutions could aim to structure members' everyday activities, for example by supporting sharing of physical goods, or aim to coordinate members to influence outcomes in other institutions, as in online activism. This may not sound too different from the rallying call of the persuasive technologists, but I think that to do this well we will need much richer understandings of social and economic life than that work has used thus far. Such understandings should be accompanied by much more vigorous discourse on the ethical constraints and obligations of designers and operators of information systems. Let's sum up. Abstractly, sustainability or unsustainability is a property of a system in an environment over a period of time. [Slide: Sustainability is...] Concretely and globally, however, at least in one prevailing view from international sustainable development discourse, a transition to sustainability aims to meet human needs; sustain the life support systems of the planet; and reduce hunger and poverty. In this discourse needs are distinguished from wants and defined as including food and nutrition, care for children, shelter, education, and employment. [Slide: Sustainability will be achieved by...] This transition will be achieved by changing institution-infrastructure systems to allocate effort and resources away from non-sustainability-oriented goals and toward sustainability-oriented goals. [Slide: Institution-infrastructure systems are changed...] Change in institution-infrastructure systems is achieved mainly by authorized actors in particular institutional locations in particular moments such as collective-choice or constitional-choice situations. Importantly, however, such actors respond to the conditions of their environment, which is comprised in significant part of other institution-infrastructure systems, which outside actors may be able to influence. [Slide: HCI can support institutional change by...] HCI researchers can support institutional change toward sustainability by collaborating with specifically institutionally located actors in efforts to change institutional practices, perhaps especially in moments involving the design of new institutional information systems. [Slide: ...and by...] HCI researchers can also create new institutions through software. These answers give a rationale and more concrete direction for the next steps outlined by workshop participants. [Slide: blank.] Some sustainable HCI researchers have observed that the "big definitions" of sustainability do not give us much help as information systems designers and operators, and can even be overwhelming in trying to understand what we can do. I hope I have made some progress in building an argument that this is not because "big definitions" are irrelevant and that we should therefore leave practical interpretations of sustainability entirely to users or to our own understandings gleaned from popular discourse, as has been done so far and even explicitly argued for. Rather, I believe that the big definitions do not give us much help so far because we have yet to do the theoretical work of connecting them to information systems design and practice. Doing this work gives us answers to the theoretical questions we passed over in the workshop. And these answers can help us orient and evaluate information systems design and practice. These are far from the only answers possible. But I hope they show that coherent answers are possible, valuable, and worth arguing about. One indicator of the importance of theory is that different answers to theoretical questions point us to different activities and different self-understandings of our activities. I have drawn on particular literatures to present a possible future sustainable HCI research agenda focused on institutions and infrastructures by claiming that sustainability will be achieved by changing these systems. To some extent this approach focuses on the orderly, regular, and formally prescribed aspects of sociotechnical-ecological systems. The dynamics of such systems have less predictable aspects which may be just as important and which may lie outside the rules, norms, and "rational" strategies that govern institutional life. Social ecologists, for example, foreground "transactions" between the social and material aspects of complex systems, domains they see as interconnected but incommensurable and ontologically separate. This view has wide-reaching implications for research and sustainability practice, including for example the notion that sustainability may be achieved by linking domains to prevent self-reinforcing activities in one domain from negatively affecting other domains. This view could complement the approach I have advanced here in structuring our understanding of situations that exceed institutional analysis. More broadly, the utility of any theoretical framework will be evaluated by how well it helps us understand the situations in which we hope to intervene, and to do so in ways that align with our, and other stakeholders', intentions. For us to move forward, at least three things are needed. First, HCI researchers working as theorists must build trans-scalar, transdisciplinary theoretical frameworks to orient and evaluate our practical work. These frameworks should bridge the natural and social sciences and operationalize this research in ways that guide design. Second, as members of a research community, and as citizens of planet earth concerned with sustainability as a practical ethical imperative, we must do the practical, institutionally, infrastructurally, and ecologically situated work. We must take our own advice, and reach out to practitioners in many sectors to build new systems that support institutional change toward sustainability goals. And third, as educators, we must train the next generation of researchers and practitioners so that they understand the stakes of these challenges and are adequately equipped, conceptually and practically, to engage them. [Slide: book covers again.] It is my firm conviction that we are equal to this task. Thank you.