In this paper we consider various genres of citizen science from the perspective of citizen participants. As a mode of scientific inquiry, citizen science has the potential to "scale up" scientific data collection efforts and increase lay engagement with science. However, current technological directions risk losing sight of the ways in which citizen science is actually practiced. As citizen science is increasingly used to describe a wide range of activities, we begin by presenting a framework of citizen science genres. We then present findings from four interlocking qualitative studies and technological interventions of community air quality monitoring efforts, examining the motivations and capacities of citizen participants and characterizing their alignment with different types of citizen science. Based on these studies, we suggest that data acquisition involves complex multi-dimensional tradeoffs, and the commonly held view that citizen science systems are a win-win for citizens and science may be overstated.

India and other economies in the Global South are undergoing a proliferation in public Wi-Fi, with large-scale deployments from industry and government. In this paper, we report on a qualitative study on public Wi-Fi conceptions as held by urban Indians, textit{a priori} to connecting to a network. Our findings show that prior public Wi-Fi users and non-users alike raised a surprising range and depth of conceptions---ranging from suspicion of operators' intentions to monetize, to concerns about sexual image morphing, to fears of phone wipeouts, to aspiration---which were informed by popular media, BlueTooth cultures, and social learning. We found these conceptions of Wi-Fi networks to significantly influence adoption of public Wi-Fi. With enormous investments in public Wi-Fi initiatives, we call for network providers to address these deep conceptions among emerging users; by suggesting ways to build public awareness, better user experiences, and business model innovation.

As access to the Internet improves globally, we argue that speed is important for accelerated and full-fledged exploration of the Internet. We provided high-speed broadband service plans and Wi-Fi access points to 12 Internet-using Indian households in Delhi and Lucknow for three months. We sought to understand uptake, trajectories, behaviours, and developmental impact of the speed of the Internet on the daily lives of our respondents through a multi-phased study (baseline, in-situ usage, follow-up). Our findings suggest that high-speed Wi-Fi led to 2-3x increase in online activity and higher-bandwidth activities; spurred Internet skilling and instrumental uses online; shifted the time and space of device access; created social currency; and transformed the construct of Internet for the households. Ultimately, 8 out of the 12 households switched to high-speed Wi-Fi after the study concluded. We discuss considerations for policy and infrastructure deployments in introducing and onboarding new and existing users living with slow speeds to higher-quality networks.

Mobile data usage is on the rise globally. In emerging regions, mobile data is particularly expensive and suffers from the lack of price and data usage transparency needed to make informed decisions about Internet use. To measure and address this problem, we designed SmartBrowse, an Internet proxy system that shows mobile data usage information and provides controls to avoid overspending. In this paper, we discuss the results of a 10-week study with SmartBrowse, involving 299 participants in Ghana. Half the users were given SmartBrowse, and the other half was given a regular Internet experience. Our findings suggest that, compared with the control group, using SmartBrowse led to a significant reduction in Internet credit spend and increased online activity among SmartBrowse users, while providing the same or better mobile Internet user experience. Additionally, SmartBrowse users who were prior mobile data non-users increased their webpage views while spending less money than control users. Our discussion contributes to the understanding of how forward-looking ICTD research in the wild can empower mobile data users, in this case, through increased price transparency.

We present results from a qualitative study examining how professionals living and working in Nairobi, Kenya regularly use ICT in their everyday lives. There are two contributions of this work for the HCI community. First, we provide empirical evidence demonstrating constraints our participants encountered when using technology in an infrastructure-poor setting. These constraints are limited bandwidth, high costs, differing perceptions of responsiveness, and threats to physical and virtual security. Second, we use our findings to critically evaluate the "access, anytime and anywhere" construct shaping the design of future technologies. We present an alternative vision called deliberate interactions--a planned and purposeful interaction style that involves offline preparation and discuss ways ICT can support this online usage behavior.

Researchers are developing mobile sensing platforms to facilitate public awareness of environmental conditions. However, turning such awareness into practical community action and political change requires more than just collecting and presenting data. To inform research on mobile environmental sensing, we conducted design fieldwork with government, private, and public interest stakeholders. In parallel, we built an environmental air quality sensing system and deployed it on street sweeping vehicles in a major U.S. city; this served as a research vehicle"by grounding our interviews and affording us status as environmental action researchers. In this paper, we present a qualitative analysis of the landscape of environmental action, focusing on insights that will help researchers frame meaningful technological interventions.

Claim Mobile is a platform designed to support a project that subsidizes healthcare by reimbursing health service providers in Uganda for treatment of patients with sexually transmitted infections. As with many development projects, the Uganda Output-Based Aid (OBA) project involves a number of stakeholders: the service providers, the project implementers, the financiers, and the Ugandan government. Design of an appropriate solution requires meeting the various and conflicting requirements of all of these stakeholders. In this paper we detail the rapid design and testing of a pilot implementation of a mobile and web-based system for processing claims forms, based on two prior field visits to Uganda. Based on a comparative device study, semi-structured interviews, health clinic surveys, and a brief deployment, we affirm the selection of the mobile phone as a platform from the health clinic perspective, and further suggest that effective design for development requires more than addressing requirements of the the “users” of the mobile phones but also all the other stakeholders involved, who may have conflicting requirements.

This paper examines two parallel case studies to promote remote medical consultation in Ghana. These projects, initiated independently by different researchers in different organizations, both deployed ICT solutions in the same medical community in the same year. The Ghana Consultation Network currently has over 125 users running a Web-based application over a delay-tolerant network of servers. OneTouch MedicareLine is currently providing 1700 doctors in Ghana with free mobile phone calls and text messages to other members of the medical community. We present the consequences of (1) the institutional context and identity of the investigators, as well as specific decisions made with respect to (2) partnerships formed, (3) perceptions of technological infrastructure, and (4) high-level design decisions. In concluding, we discuss lessons learned and high-level implications for future ICTD research agendas.

Poor air quality is a global health issue, causing serious problems like asthma, cancer, and heart disease around the world. Earlier this decade, the World Health Organization estimated that three million people die each year from the effects of air pollution [6]. Unfortunately, while variations in air quality are significant, today's air quality monitors are very sparsely deployed. To address this visibility gap, the Common Sense project is developing participatory sensing systems that allow individuals to measure their personal exposure, groups to aggregate their members' exposure, and activists to mobilize grassroots community action.

Computer-mediated communication systems can be used to bridge the gap between doctors in underserved regions with local shortages of medical expertise and medical specialists worldwide. To this end, we describe the design of a prototype remote consultation system intended to provide the social, institutional and infrastructural context for sustained, self-organizing growth of a globally-distributed Ghanaian medical community. The design is grounded in an iterative design process that included two rounds of extended design fieldwork throughout Ghana and draws on three key design principles (social networks as a framework on which to build incentives within a self-organizing network; optional and incremental integration with existing referral mechanisms; and a weakly-connected, distributed architecture that allows for a highly interactive, responsive system despite failures in connectivity). We discuss initial experiences from an ongoing trial deployment in southern Ghana.

In this paper, we report on design-oriented fieldwork and design research conducted over a six-month period in urban centers in the United States and Kenya. The contributions of this work for the CHI/CSCW community are empirical and methodological. First, we describe how recent design discourse around "designing technology for religion" creates an artificial distinction between instrumental and religious ICT use, particularly in developing regions. As illustrative examples, we relate three themes developed in the course of our fieldwork, which we term mindfulness, watchfulness, and embeddedness, to both "secular" and "religious" aspects of life in the communities studied. Second, we make a methodological contribution by describing how we used design sketches of speculative design concepts to extend and complement our fieldwork. By producing these sketches and soliciting feedback, we elicited additional data about how participants viewed the relationship between religion and ICT and prompted self-reflection on our own ideas.

While tactical command. control and communication environments might appear to be entirely instrumental in nature, they nevertheless provide a setting for social interaction. This paper describes how such interaction occurs in a particular naval tactical command and control system, focusing on the shared perspectives created by the organizational, administrative and professional aspects of the environment and on issues of self-presentation. It is argued that the complexity and multiplicity of interactional regions in this environment lead to problematic situations for key actors, and that these problems may have relevance to future computing environments.

Spontaneous multi-party interaction -- conversation among groups of three or more participants -- is part of daily life. While automated modeling of such interactions has received increased attention in ubiquitous computing research, there is little applied research on the organization of this highly dynamic and spontaneous sociable interaction within small groups. We report here on an applied conversation analytic study of small-group sociable talk, emphasizing structural and temporal aspects that can inform computational models. In particular, we examine the mechanics of multiple simultaneous conversational floors -- how participants initiate a new floor amidst an on-going floor, and how they subsequently show their affiliation with one floor over another. We also discuss the implications of these findings for the design of "smart" multi-party applications.

Pervasive personal communication technologies offer the potential for important social benefits for individual users, but also the potential for significant social difficulties and costs. In research on face-to-face social interaction, ambiguity is often identified as an important resource for resolving social difficulties. In this paper, we discuss two design cases of personal communication systems, one based on fieldwork of a commercial system and another based on an unrealized design concept. The cases illustrate how user behavior concerning a particular social difficulty, unexplained unresponsiveness, can be influenced by technological issues that result in interactional ambiguity. The cases also highlight the need to balance the utility of ambiguity against the utility of usability and communicative clarity.

This paper presents a novel application of speech emotion recognition: estimation of the level of conversational engagement between users of a voice communication system. We begin by using machine learning techniques, such as the support vector machine (SVM), to classify users' emotions as expressed in individual utterances. However, this alone fails to model the temporal and interactive aspects of conversational engagement. We therefore propose the use of a multilevel structure based on coupled hidden Markov models (HMM) to estimate engagement levels in continuous natural speech. The first level is comprised of SVM-based classifiers that recognize emotional states, which could be (e.g.) discrete emotion types or arousal/valence levels. A high-level HMM then uses these emotional states as input, estimating users' engagement in conversation by decoding the internal states of the HMM. We report experimental results obtained by applying our algorithms to the LDC EMO- TIONAL PROSODY and CALLFRIEND speech corpora.

This paper presents a mobile audio space intended for use by gelled social groups. In face-to-face interactions in such social groups, conversational floors change frequently, e.g., two participants split off to form a new conversational floor, a participant moves from one conversational floor to another, etc. To date, audio spaces have provided little support for such dynamic regroupings of participants, either requiring that the participants explicitly specify with whom they wish to talk or simply presenting all participants as though they are in a single floor. By contrast, the audio space described here monitors participant behavior to identify conversational floors as they emerge. The system dynamically modifies the audio delivered to each participant to enhance the salience of the participants with whom they are currently conversing. We report a user study of the system, focusing on conversation analytic results.

This paper presents an exploratory study of college-age students using two-way, push-to-talk cellular radios. We describe the observed and reported use of cellular radio by the participants. We discuss how the half-duplex, lightweight cellular radio communication was associated with reduced interactional commitment, which meant the cellular radios could be used for a wide range of conversation styles. One such style, intermittent conversation, is characterized by response delays. Intermittent conversation is surprising in an audio medium, since it is typically associated with textual media such as instant messaging. We present design implications of our findings.

In addition to providing information to individual visitors, electronic guidebooks have the potential to facilitate social interaction between visitors and their companions. However, many systems impede visitor interaction. By contrast, our electronic guidebook, Sotto Voce, has social interaction as a primary design goal. The system enables visitors to share audio information - specifically, they can hear each other's guidebook activity using a technologically mediated audio eavesdropping mechanism. We conducted a study of visitors using Sotto Voce while touring a historic house. The results indicate that visitors are able to use the system effectively, both as a conversational resource and as an information appliance. More surprisingly, our results suggest that the technologically mediated audio often cohered the visitors' conversation and activity to a far greater degree than audio delivered through the open air

This paper reports findings from a study of how a guidebook was used by pairs of visitors touring a historic house. We describe how the guidebook was incorporated into their visit in four ways: shared listening, independent use, following one another, and checking in on each other. We discuss how individual and groupware features were adopted in support of different visiting experiences, and illustrate how that adoption was influenced by social relationships, the nature of the current visit, and any museum visiting strategies that the couples had. Finally, we describe how the guidebook facilitated awareness between couples, and how awareness of non-guidebook users (strangers) influenced use.

The standard mechanisms for query selectivity estimation used in relational database systems rely on properties that are specific to the attribute types. The query optimizer in an extensible database system is, in general, unable to exploit these mechanisms for user-defined types, forcing the database extender to invent new estimation mechanisms. In this paper, we discuss extensions to the generalized search tree (GiST) that simplify the creation of user-defined selectivity estimation methods. An experimental comparison of such methods with multidimensional estimators from the literature has demonstrated very competitive results.

The object-relational database management system (ORDBMS) offers many potential benefits for scientific, multimedia and financial applications. However work remains in the integration of domain-specific class libraries into ORDBMS query processing. A major problem is that the standard mechanisms for query selectivity estimation, taken from relational database systems, rely on properties specific to the standard data types; creation of new mechanisms remains extremely difficult because the software interfaces provided by vendors are relatively low-level. We discuss extensions of the generalized search tree, or GiST, to support a higher level but less type-specific approach. Specifically, we discuss the computation of selectivity estimates with confidence intervals using a variety of index based approaches and present results from an experimental comparison of these methods with several estimators from the literature.

The generalized search tree, or GiST, defines a framework of basic interfaces required to construct a hierarchical access method for database systems. As originally specified, GiST only supports record selection. We show how a small number of additional interfaces enable GiST to support a much larger class of operations. Members of this class, which includes, nearest-neighbor and ranked search, user-defined aggregation and index-assisted selectivity estimation, are increasingly common in new database applications. The advantages of implementing these operations in the GiST framework include reduction of user development effort and the ability to use industrial strength concurrency and recovery mechanisms provided by expert implementers.

The Mariposa distributed data manager uses an economic model for managing the allocation of both storage objects and queries to servers. In this paper, we present extensions to the economic model which support replica management, as well as our mechanisms for propagating updates among replicas. We show how our replicacontrol mechanism can be used to provide consistent, although potentially stale, views of data across many machines without expensive pertransaction synchronization. We present a rule-based con#ict resolution mechanism, which can be usedto enhancetraditional time-stamp serialization. We discuss the e#ects of our replica system on query processing for both read-only and read-write queries. We further demonstrate how the replication model and mechanisms naturally support name service in Mariposa. 1 Introduction In this paper we describe replica managementin the Mariposa distributed data base management system #STON94a#. There has been considerable research devoted to stu...

We describe the design of Mariposa, an experimental distributed data management system that provides high performance in an environment of high data mobility and heterogeneous host capabilities. The Mariposa design unifies the approaches taken by distributed file systems and distributed databases. In addition, Mariposa provides a general, flexible platform for the development of new algorithms for distributed query optimization, storage management, and scalable data storage structures. This flexibility is primarily due to a unique rule-based design that permits autonomous, local-knowledge decisions to be made regarding data placement, query execution location, and storage management.>