Rick Wash

By Cliff Lampe, Rick Wash, Alcides Velasquez, and Elif Ozkaya

Socio-technical systems, or online communities, often depend on the participation and contributions of large sets of users.  This study examines the case of Everything2.com users from the theoretical perspectives of Uses and Gratifications and organizational commitment to create models of why both anonymous and registered users of the site participate.  We find evidence that users may continue to participate in a site for different reasons than those that led them to the site.  Feelings of belonging to a site are important for both anonymous and registered users across different types of uses.  Social and cognitive factors seem to be more important than issues of usability in predicting contribution to the site.

Cliff Lampe, Rick Wash, Alcides Velasquez, and Elif Ozkaya. “Motivations to Participate in Online Communities.” ACM Conference on Human Factors in Computing (CHI) (2010).

Download: PDF

Home computer systems are frequently insecure because they are administered by untrained, unskilled users.  The rise of botnets has amplified this problem; attackers can compromise these computers, aggregate them, and use the resulting network to attack third parties.  Despite a large security industry that provides software and advice, home computer users remain vulnerable.  I investigate how home computer users make security-relevant decisions about their computers.  I identify eight `folk models’ of security threats that are used by home computer users to decide what security software to use, and which security advice to follow: four different conceptualizations of `viruses’ and other malware, and four different conceptualizations of `hackers’ that break into computers.  I illustrate how these models are used to justify ignoring some security advice.  Finally, I describe one reason why botnets are so difficult to eliminate: they have been cleverly designed to take advantage of gaps in these models so that many home computer users do not take steps to protect against them.

Rick Wash.  ”Folk Models of Home Computer Security.” Symposium on Usable Privacy and Security (SOUPS) 2010.

Download: PDF

By Emilee Rader and Rick Wash

Collaborative tagging systems have the potential to produce socially constructed information organization schemes. The effectiveness of tags for finding and re-finding information depends upon how individual users choose tags; however, influences on users’ tag choices are poorly understood. We quantitatively test competing hypotheses from the literature concerning these choices, using data from del.icio.us (a collaborative tagging system for organizing web bookmarks) and a computer model of possible tag choice strategies. We find evidence that users choose tags in a pattern consistent with personal information management goals, rather than as a result of social influence.

Emilee Rader and Rick Wash. “Influences on Tag Choices in del.icio.us,” Proceedings of Computer Supported Cooperative Work (CSCW), November 2008

Download: PDF (Appendix)

By Rick Wash and Emilee Rader

Users of social computing websites are both producers and consumers of the information found on the site. This creates a novel problem for web-based software applications: how can website designers induce users to produce information that is useful for others? We study this question by interviewing users of the social bookmarking website del.icio.us. We find that for the users in our sample, metadata reflecting who bookmarked a webpage better supports information seeking than free-form keyword metadata (tags). We explain this finding by describing differences in the way that the design of del.icio.us motivates users to contribute by providing personal benefits for bookmarking and tagging.

Rick Wash and Emilee Rader. “Public Bookmarks and Private Benefits: An Analysis of Incentives in Social Computing,“ Proceedings of the ASIS&T Annual Meeting. December 2007

Download: PDF

By Rick Wash and Jeff MacKie-Mason

Humans are “smart components” in a system, but cannot be directly programmed to perform; rather, their autonomy must be respected as a design constraint and incentives provided to induce desired behavior. Sometimes these incentives are properly aligned, and the humans don’t represent a vulnerability. But often, a misalignment of incentives causes a weakness in the system that can be exploited by clever attackers. Incentive-centered design tools help us understand these problems, and provide design principles to alleviate them. We describe incentive-centered design and some tools it provides. We provide a number of examples of security problems for which Incentive Centered Design might be helpful. We elaborate with a general screening model that offers strong design principles for a class of security problems.

Rick Wash and Jeffrey K. MacKie-Mason. “Security When People Matter: Structuring Incentives for User Behavior.” Proceedings of the International Conference on Electronic Commerce, August 2007.

Download: PDF

By Rick Wash, Libby Hemphill, and Paul Resnick

The RideNow Project is designed to help individuals within a group or organization coordinate ad hoc shared rides. This paper describes three design decisions the RideNow team made in order to allow incremental adoption and evolution and to capitalize on local conditions. (1) The system allows users to interact with the system through email or Web, because we anticipate that email will be most convenient when there are few users but the Web interface will be more useful as the number of users increase. (2) The system does not force structure on user-entered data such as dates, times, and locations, instead allowing conventions to emerge. (3) We use the group’s shared physical spaces to provide additional information about ride sharing activity.

Rick Wash, Libby Hemphill, and Paul Resnick. “Design Decisions in the RideNow Project”.  Proceedings of the ACM Conference on Supporting Group Work (GROUP), 2005

Download: PDF

By Thede Loder, Marshall Van Alstyne, and Rick Wash

We explore an alternative approach to spam based on economic rather than technological or regulatory screening mechanisms. We employ a model of email value which supports two intuitive notions: 1) mechanisms designed to promote valuable communication can often outperform those designed merely to block wasteful communication, and 2) designers of such mechanisms should shift focus away from the information in the message to the information known to the sender. We then use principles of information asymmetry to cause people who knowingly misuse communication to incur higher costs than those who do not. In certain cases, though not all, we can show this approach leaves recipients better off than even an idealized or “perfect” filter that costs nothing and makes no mistakes. Our mechanism also accounts for individual differences in opportunity costs, and allows for bi-directional wealth transfers while facilitating both sender signaling and recipient screening.

Thede Loder, Marshall Van Alstyne, and Rick Wash. An Economic Solution to the Spam Problem. Proceedings of the ACM Conference on Electronic Commerce, 2004.

Download: PDF, PS

* This material is based upon work supported by the National Science Foundation under Grant No. 0114368.