Motivations to Participate in Online Communities

December 13th, 2009 Comments Off

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

Gratifications and organizational commitment to createcontext of participation in online communities. Uses and

Motivating Contributions for Home Computer Security

October 24th, 2009 Comments Off

Recently, malicious computer users have been compromising computers en masse and combining them to form coordinated botnets. The rise of botnets has brought the problem of home computers to the forefront of security.  Home computer users commonly have insecure systems; these users do not have the knowledge, experience, and skills necessary to maintain a secure system.  I take steps toward designing a socio-technical system that will hopefully help home computer users make better security decisions.  Designing such a system requires additional knowledge before a successful system can be developed.

First, more information is needed about the knowledge and skills that home computer users currently possess. I conducted an interview study of home computer users and identified eight distinct mental models of security threats; four are models of “viruses,” and four are models of “hackers.”  The respondents in this study use the models to decide which security precautions should be used and which can be ignored.

Second, to share information, users need an incentive to exert the time and effort required for sharing. I describe two mechanisms that can be used in social computing systems to encourage contribution.   I illustrate the first mechanism, the side effect mechanism, by describing how it is used in a popular social bookmarking website.  I also illustrate a design feature that is important when applying this mechanism: incentive alignment. The second mechanism that I describe is technically simple: set a minimum threshold and exclude users who don’t contribute enough.  I develop a theory of how users are likely to respond to such a mechanism and use that theory to characterize when such a mechanism should be used.

Finally, I bring all of these findings together to suggest some preliminary design features for a socio-technical security system to help home computer users.  While there are many unanswered questions, these design features can serve as a starting point for future work in the area.

Download: PDF

Recently, malicioucomputer users have been compromising computers en masse and combining them to form coordinated botnets. The rise of botnets has brought the problem of home computers to the forefront of security.  Home computer users commonly have insecure systems; these users do not have the knowledge, experience, and skills necessary to maintain a secure system.  I take steps toward designing a socio-technical system that will hopefully help home computer users make better security decisions.  Designing such a system requires additional knowledge before a successful system can be developed.
First, more information is needed about the knowledge and skills that home computer users currently possess. I conducted an interview study of home computer users and identified eight distinct mental models of security threats; four are models of “viruses,” and four are models of “hackers.”  The respondents in this study use the models to decide which security precautions should be used and which can be ignored.
Second, to share information, users need an incentive to exert the time and effort required for sharing. I describe two mechanisms that can be used in social computing systems to encourage contribution.   I illustrate the first mechanism, the side effect mechanism, by describing how it is used in a popular social bookmarking website.  I also illustrate a design feature that is important when applying this mechanism: incentive alignment. The second mechanism that I describe is technically simple: set a minimum threshold and exclude users who don’t contribute enough.  I develop a theory of how users are likely to respond to such a mechanism and use that theory to characterize when such a mechanism should be used.
Finally, I bring all of these findings together to suggest some preliminary design features for a socio-technical security system to help home computer users.  While there are many unanswered questions, these design features can serve as a starting point for future work in the are

Folk Models of Home Computer Security

October 24th, 2009 Comments Off

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

Using a Minimum Threshold to Motivate Contributions to Social Computing

October 18th, 2009 Comments Off

By Rick Wash and Jeff MacKie-Mason

Social computing systems collect, aggregate, and share user-contributed content, and therefore depend on contributions from users to function properly. However, humans are intelligent beings and cannot be programmed to behave; system designers must provide incentives to encourage users to contribute. We explore the behavioral consequences of one simple incentive mechanism: require users to contribute a minimum amount of information before they are granted access to the system. Users with a high marginal cost of contribution will stop using the system, but users with a moderate marginal cost will increase their contribution, frequently leading to greater benefits for everyone still using the system. Additionally, if contributions are collaborative and build upon each other, then existing contributors are likely to slightly decrease their contributions, leading to a more ’equal’ distribution of contributions. We show that this mechanism often leads to increased contributions, and provide concrete design advice for using this mechanism in social computing systems.

Rick Wash and Jeff MacKie-Mason. “Using a Minimum Threshold to Motivate Contributions to Social Computing,” Working Paper, June 2009.

Download: PDF

A Social Mechanism for Home Computer Security

October 18th, 2009 Comments Off

By Rick Wash and Jeff MacKie-Mason

Hackers have learned to leverage the enormous number of poorly protected home computers by turning them into a large distributed system (known as a botnet), making home computers an important frontier for security research. They present special problems: owners are unsophisticated, and usage profiles are varied making onesize-fits-all firewall policies ineffective. We propose a social firewall that collects security decisions and both user and usage characteristics, and provides users with personalized information to assist with allow/deny recommendations. To succeed, a social firewall must deal with at least three user behavior issues: why contribute private information? why make effort to provide quality information? and, how to prevent manipulation by adversaries? We sketch an incentive-centered design approach to each problem. We provide an economic model and some analytic results for a solution to the fundamental problem: why contribute? We show that an excludable public goods mechanism can achieve a better outcome than a system without social motivators.

Rick Wash and Jeff MacKie-Mason. “A Social Mechanism for Home Computer Security,” Presented at the Workshop on Information Systems and Economics (WISE), December 2008.

Download: PDF

Influences on Tag Choice in del.icio.us

October 18th, 2009 Comments Off

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)

Mental Models of Home Computer Security

October 18th, 2009 Comments Off

By Rick Wash

Users of home computer systems are becoming increasingly aware of the need for computer and information security systems. The market for security software for home users is growing rapidly, and includes anti-virus software, anti-spyware software, personal rewall software, personal intrusion detection / prevention systems, computer login / password / fi ngerprint systems, and intrusion recovery software. This software often requires security-relevant decisions be made by the home users, though most home users have little of the technical training and knowledge needed to make those decisions.

Though home computer users have little technical training, they do have some idea of the security threats they face and the potential countermeasures; indeed, the market for home security software is quite active. I conducted a series of 23 semi-interviews to better understand how home computer users think about security threats and security software. While home computer users did not have the complex, sophisticated mental models of computer security experts, they did have a couple of simple models that helped them make security-related decisions. These models led to a number of good security choices, but also led to a number of vulnerabilities that have been exploited by modern botnets. By understanding these mental models, home computer security technologies can be designed to address the vulnerabilities left by these models, and to take advantage of the knowledge that home users actually do possess.

Rick Wash. “Mental Models of Home Computer Security,” Extended Abstract at SOUPS (Symposium on Usable Privacy and Security) 2008 Poster Session. May 2008.

Download: PDF

Understand del.icio.us Tag Choice Using Simulations

October 18th, 2009 Comments Off

By Rick Wash and Emilee Rader

Understanding how users choose tags can help researchers better understand how tagging systems can be used and how to design better tagging systems for the future. We developed a simulation of del.icio.us, a popular social bookmarking tool, that allowed us to simulate users choosing tags using one of four possible strategies for tag choice found in the literature. We then compared the resulting tag choices with empirical data retrieved from del.icio.us to determine which tag choice strategies would result in choices most similar to those seen in the real world. We were able to rule out three of the strategies as unlikely to be the primary means by which tags are chosen on del.icio.us.

Rick Wash and Emilee Rader, “Understanding del.icio.us Tag Choice Using Simulations,” Presented at iConference 2008, Paper Track. February 2008

Download: PDF

An Economic Solution to Unsolicited Communication

October 18th, 2009 Comments Off

By Thede Loder, Marshall van Alstyne, and Rick Wash

If communication involves some transactions cost to both sender and recipient, what policy ensures that correct messages – those with positive social surplus — get sent? Filters block messages that harm recipients but benefit senders by more than transactions costs. Taxes can block positive value messages, and allow harmful messages through. In contrast, we propose an “Attention Bond,” allowing recipients to define a price that senders must risk to deliver the initial message.

The underlying problem is first-contact information asymmetry with negative externalities. Uninformed senders waste recipient attention through message pollution. Requiring attention bonds creates an attention market, effectively applying the Coase Theorem to price this scarce resource. In this market, screening mechanisms shift the burden of message classification from recipients to senders, who know message content. Price signals can also facilitate decentralized two-sided matching. In certain limited cases, this leads to greater welfare than use of even “perfect” filters.

Thede Loder, Marshall Van Alstyne, and Rick Wash. “An Economic Solution to Unsolicited Communications,” Advances in Economic Analysis and Policy, vol. 6, no. 1, Berkeley Electronic Press 2006

Download: Journal page (Cached PDF)

Public Bookmarks and Private Benefits: An Analysis of Incentives in Social Computing

October 18th, 2009 Comments Off

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