Reid Priedhorsky

Creating, destroying, and restoring value in wikipedia

Wikipedias brilliance and curse is that any user can edit any of the encyclopedia entries. We introduce the notion of the impact of an edit, measured by the number of times the edited version is viewed. Using several datasets, including recent logs of all article views, we show that an overwhelming majority of the viewed words were written by frequent editors and that this majority is increasing. Similarly, using the same impact measure, we show that the probability of a typical article view being damaged is small but increasing, and we present empirically grounded classes of damage. Finally, we make policy recommendations for Wikipedia and other wikis in light of these findings.

Lurking? cyclopaths?: a quantitative lifecycle analysis of user behavior in a geowiki

Online communities produce rich behavioral datasets, e.g., Usenet news conversations, Wikipedia edits, and Facebook friend networks. Analysis of such datasets yields important insights (like the long tail of user participation) and suggests novel design interventions (like targeting users with personalized opportunities and work requests). However, certain key user data typically are unavailable, specifically viewing, pre-registration, and non-logged-in activity. The absence of data makes some questions hard to answer; ac- cess to it can strengthen, extend, or cast doubt on previous results. We report on analysis of user behavior in Cyclopath, a geographic wiki and route-finder for bicyclists. With access to viewing and non-logged-in activity data, we were able to: (a) replicate and extend prior work on user lifecycles in Wikipedia, (b) bring to light some pre-registration activity, thus testing for the presence of educational lurking, and (c) demonstrate the locality of geographic activity and how editing and viewing are geographically correlated.

Eliciting and focusing geographic volunteer work

Open content communities such as wikis derive their value from the work done by users. However, a key challenge is to elicit work that is sufficient and focused where needed. We address this challenge in a geographic open content community, the Cyclopath bicycle route finding system. We devised two techniques to elicit and focus user work, one using familiarity to direct work opportunities and another visually highlighting them. We conducted a field experiment, finding that (a) the techniques succeeded in eliciting user work, (b) the distribution of work across users was highly unequal, and (c) user work benefitted the community (reducing the length of the average computed route by 1 kilometer).

Capturing, sharing, and using local place information

With new technology, people can share information about everyday places they go; the resulting data helps others find and evaluate places. Recent applications like Dodgeball and Sharescape repurpose everyday place information: users create local place data for personal use, and the systems display it for public use. We explore both the opportunities -- new local knowledge, and concerns -- privacy risks, raised by this implicit information sharing. We conduct two empirical studies: subjects create place data when using PlaceMail, a location-based reminder system, and elect whether to share it on Sharescape, a community map-building system. We contribute by: (1) showing location-based reminders yield new local knowledge about a variety of places, (2) identifying heuristics people use when deciding what place-related information to share (and their prevalence), (3) detailing how these decision heuristics can inform local knowledge sharing system design, and (4) identifying new uses of shared place information, notably opportunistic errand planning.

The computational geowiki: what, why, and how

Google Maps and its spin-offs are highly successful, but they have a major limitation: users see only pictures of geographic data. These data are inaccessible except by limited vendor-defined APIs, and associated user data are weakly linked to them. But some applications require access, specifically geowikis and computational geowikis. We present the design and implementation of a computational geowiki. We also show empirically that both geowiki and computational geowiki features are necessary for a representative domain, bicycling, because (a) cyclists have useful knowledge unavailable except from cyclists and (b) cyclist-oriented automatic route-finding is enhanced by user input. Finally, we derive design implications: for example, user contributions presented within a route description are useful, and wikis should support contribution of opinion as well as fact.

How a personalized geowiki can help bicyclists share information more effectively

The bicycling community is focused around a real-world activity -- navigating a bicycle -- which requires planning within a complex and ever-changing space. While all the knowledge needed to find good routes exists, it is highly distributed. We show, using the results of surveys and interviews, that cyclists need a comprehensive, up-to-date, and personalized information resource. We introduce the personalized geowiki, a new type of wiki which meets these requirements, and we formalize the notion of geowiki. Finally, we state some general prerequisites for wiki contribution and show that they are met by cyclists.

bumpy, caution with merging: an exploration of tagging in a geowiki

We introduced tags into the Cyclopath geographic wiki for bicyclists. To promote the creation of useful tags, we made tags wiki objects, giving ownership of tag applications to the community, not to individuals. We also introduced a novel interface that lets users fine-tune their routing preferences with tags. We analyzed the Cyclopath tagging vocabulary, the relationship of tags to existing annotation techniques (notes and ratings), and the roles users take on with respect to tagging, notes, and ratings. Our findings are: two distinct tagging vocabularies have emerged, one around each of the two main types of geographic objects in Cyclopath; tags and notes have overlapping content but serve distinct purposes; users employ both ratings and tags to express their route-finding preferences, and use of the two techniques is moderately correlated; and users are highly specialized in their use of tags and notes. These findings suggest new design opportunities, including semi-automated methods to infer new annotations in a geographic context.

Recommending routes in the context of bicycling: algorithms, evaluation, and the value of personalization

Users have come to rely on automated route finding services for driving, public transit, walking, and bicycling. Current state of the art route finding algorithms typically rely on objective factors like time and distance; they do not consider subjective preferences that also influence route quality. This paper addresses that need. We introduce a new framework for evaluating edge rating prediction techniques in transportation networks and use it to explore ten families of prediction algorithms in Cyclopath, a geographic wiki that provides route finding services for bicyclists. Overall, we find that personalized algorithms predict more accurately than non-personalized ones, and we identify two algorithms with low error and excellent coverage, one of which is simple enough to be implemented in thin clients like web browsers. These results suggest that routing systems can generate better routes by collecting and analyzing users subjective preferences.

Wiki grows up: arbitrary data models, access control, and beyond

Ward Cunninghams vision for the wiki was that it would be the simplest online database that could possibly work. We consider here a common manifestation of simplicity: the assumption that the objects in a wiki that can be edited (e.g., Wikipedia articles) are relatively independent. As wiki applications in new domains emerge, however, this assumption is no longer tenable. In wikis where the objects of interest are highly interdependent (e.g., geographic wikis), fundamental concepts like the revision and undoing must be refined. This is particularly so when fine-grained access control is required (as in enterprise wikis or wikis to support collaboration between citizens and government officials). We explore these issues in the context of the Cyclopath geowiki and present solutions that we have designed and have implemented or are implementing.

WikiLit: collecting the wiki and Wikipedia literature

This workshop has three key goals. First, we will examine existing and proposed systems for collecting and analyzing the research literature about wikis. Second, we will discuss the challenges in building such a system and will engage participants to design a sustainable collaborative system to achieve this goal. Finally, we will provide a forum to build upon ongoing wiki community discussions about problems and opportunities in finding and sharing the wiki research literature.