Mark S. Ackerman

Expertise networks in online communities: structure and algorithms

Web-based communities have become important places for people to seek and share expertise. We find that networks in these communities typically differ in their topology from other online networks such as the World Wide Web. Systems targeted to augment web-based communities by automatically identifying users with expertise, for example, need to adapt to the underlying interaction dynamics. In this study, we analyze the Java Forum, a large online help-seeking community, using social network analysis methods. We test a set of network-based ranking algorithms, including PageRank and HITS, on this large size social network in order to identify users with high expertise. We then use simulations to identify a small number of simple simulation rules governing the question-answer dynamic in the network. These simple rules not only replicate the structural characteristics and algorithm performance on the empirically observed Java Forum, but also allow us to evaluate how other algorithms may perform in communities with different characteristics. We believe this approach will be fruitful for practical algorithm design and implementation for online expertise-sharing communities.

The perfect search engine is not enough: a study of orienteering behavior in directed search

This paper presents a modified diary study that investigated how people performed personally motivated searches in their email, in their files, and on the Web. Although earlier studies of directed search focused on keyword search, most of the search behavior we observed did not involve keyword search. Instead of jumping directly to their information target using keywords, our participants navigated to their target with small, local steps using their contextual knowledge as a guide, even when they knew exactly what they were looking for in advance. This stepping behavior was especially common for participants with unstructured information organization. The observed advantages of searching by taking small steps include that it allowed users to specify less of their information need and provided a context in which to understand their results. We discuss the implications of such advantages for the design of personal information management tools.

Questions in, knowledge in?: a study of naver's question answering community

Large general-purposed community question-answering sites are becoming popular as a new venue for generating knowledge and helping users in their information needs. In this paper we analyze the characteristics of knowledge generation and user participation behavior in the largest question-answering online community in South Korea, Naver Knowledge-iN. We collected and analyzed over 2.6 million question/answer pairs from fifteen categories between 2002 and 2007, and have interviewed twenty six users to gain insights into their motivations,roles, usage and expertise. We find altruism, learning, and competency are frequent motivations for top answerers to participate, but that participation is often highly intermittent. Using a simple measure of user performance, we find that higher levels of participation correlate with better performance. We also observe that users are motivated in part through a point system to build a comprehensive knowledge database. These and other insights have significant implications for future knowledge generating online communities.

Beyond Boundary Objects: Collaborative Reuse in Aircraft Technical Support

Boundary objects are a critical, but understudied, theoretical construct in CSCW. Through a field study of aircraft technical support, we examined the role of boundary objects in the practical achievement of safety by service engineers. Their resolution of repair requests was preserved in the organization’s memory via three compound boundary objects. These crystallizations did not manifest a static interpretation, but instead were continually reinterpreted in light of meta-negotiations. This suggests design implications for organizational memory systems which can more fluidly represent the meta-negotiations surrounding boundary objects.

Collaborative help in chronic disease management: supporting individualized problems

Coping with chronic illness disease is a long and lonely journey, because the burden of managing the illness on a daily basis is placed upon the patients themselves. In this paper, we present our findings for how diabetes patient support groups help one another find individualized strategies for managing diabetes. Through field observations of face-to-face diabetes support groups, content analysis of an online diabetes community, and interviews, we found several help interactions that are critical in helping patients in finding individualized solutions. Those are: (1) patients operationalize their experiences to easily contextualize and share executable strategies; (2) operationalization has to be done within the larger context of sharing illness trajectories; and (3) the support groups develop common understanding towards diabetes management. We further discuss how our findings translate into design implications for supporting chronic illness patients in online community settings.

I just don't know why it's gone : maintaining informal information use in inpatient care

We conducted a field-based study examining informal nursing information. We examined the use of this information before and after the adoption of a CPOE (Computerized Provider Order Entry) system in an inpatient unit of a large teaching hospital. Before CPOE adoption, nurses used paper working documents to detail psycho-social information about patients; after the CPOE adoption, they did not use paper or digital notes as was planned. The paper describes this process and analyses how several interlocked reasons contributed to the loss of this information in written form. We found that a change in physical location, sufficient convenience, visibility of the information, and permanency of information account for some, but not all, of the outcome. As well, we found that computerization of the nursing data led to a shift in the politics of the information itself - the nurses no longer had a cohesive agreement about the kinds of data to enter into the system. The findings address the requirements of healthcare computerization to support both formal and informal work practices, respecting the nature of nursing work and the politics of information inherent in complex medical work.

The trouble with social computing systems research

Social computing has led to an explosion of research in understanding users, and it has the potential to similarly revolutionize systems research. However, the number of papers designing and building new sociotechnical systems has not kept pace. We analyze challenges facing social computing systems research, ranging from misaligned methodological incentives, evaluation expectations, double standards, and relevance compared to industry. We suggest improvements for the community to consider so that we can chart the future of our field.

Virtual gifts and guanxi: supporting social exchange in a chinese online community

Significant cultural differences persist between East and West. Software systems that have been proven to operate efficiently within one culture can fail in the context of the other, especially if they are intended to support rich social interactions. In this paper we demonstrate how a virtual currency system, not unlike ones employed by many US-based websites, evolved within a thriving Chinese online forum into an essential medium for extremely diverse and culturally specific social exchange activities. The social interactions reflect the traditional Chinese idea of guanxi, or interpersonal influence and connectedness, while at the same time incorporating the norms of a new generation of Internet users.

Personal and Ubiquitous Computing: Issue on privacy and security

These days, it seems that wherever computers are, privacy and security problems arise. From identity theft to feelings of invasion by spam email to evidence in criminal cases from surveillance cameras, privacy and security are hot topics, even in the popular press. There are many aspects of the ‘‘privacy problem’’ and the ‘‘security problem.’’ When Chris recently opened a bank account for his daughter, he witnessed many of them in an environment that was far from ‘‘ubiquitous computing.’’ First, she refused to give the bank clerk her social security number (a financial ‘‘national identity number’’ in the US) because she had learned that one must safeguard this information to protect against identity theft. The clerk, revealing as much information as many ‘‘input error’’ Web pages, simply said, ‘‘I can’t open an account for you without a social security number.’’ Chris patiently explained to his daughter that, legally, the bank was required to report certain information to the government. These data were indexed via the social security number. Then, the clerk wanted to know the mother’s maiden name (a standard question in the US for banks). Chris’ daughter got upset, since her mother’s ‘‘maiden name’’ was her surname; she had never changed it on getting married. (Even if she had, she may have changed it back upon divorce; privacy expectations change with social customs.) This time the clerk was able to provide some explanation: this was supposed to be personal information that could be used to verify her own identity in future transactions with the bank; in other words, it was a password to protect her account. But, as Chris’ daughter pointed out, it would be easy for someone, especially with Web access, to discover her mother’s current last name. The clerk suggested that any other bit of personal information could be used instead of the maiden name. It then became clear that the bank forms (infrastructure) did not have any way of recording the appropriate challenge which would remind her of the appropriate response in the future (the ‘‘password problem’’). The whole interaction left several people very suspicious of the bank, its security, and their privacy. Now, in this scenario, the computation was hardly ubiquitous! What happens in the brave new world envisioned by those of us who publish in this journal? Ubiquitous computing implies that computing is everywhere, and perhaps, so much a part of our digital environment that we cease to notice it. Since (digital) privacy seems to ‘‘happen’’ at the intersection of computers and people, and privacy is already a major concern even in the early stages of ubiquitous computing, we seem to have a major headache brewing in the near future. Also, the security issues that are already too familiar will increase as computers become invisible and ubiquitous. The sooner the research community addresses these serious concerns, the more likely we are to solve the problems, or more likely, come up with compromise solutions acceptable to most users. If ubiquitous computing is to be user-centered, the research community must tackle the human–computer interface (HCI) issues inherent in both privacy and security. For users, security and privacy are deeply intertwined. While at times they are very distinct (and it is helpful analytically to separate them), users do not always distinguish between them in considering their data or in envisioning pervasive environments. Several of the papers in this issue reinforce that premise. In any case, it is clear that user-centered pervasive environments will require new ways of looking at privacy and security. In this issue of Personal and Ubiquitous Computing, we present a selection of papers dealing with various aspects of privacy and security. Clearly, it is a rather expansive domain covering many different aspects of ubiquitous computing, and this is reflected in the C. Schmandt Media Lab, MIT, Cambridge, MA, USA

Contribution, commercialization & audience: understanding participation in an online creative community

This paper presents a qualitative study of attitudes towards participation and contribution in an online creative community. The setting of the work is an online community of practice focused on the use and development of a user-customizable music software package called Reaktor. Findings from the study highlight four emergent topics in the discourse related to user contributions to the community: contribution assessment, support for learning, perceptions of audience and tensions about commercialization. Our analysis of these topics frames discussion about the value and challenges of attending to amateur and professional users in online creative communities.