Why Wikipedia info is good and bad.

• Position: YOUR LIFE

The patterns of collaboration among Wikipedia contributors have a direct effect on the data quality of an article, according to researchers at the University of Arizona, Tucson. "Most of the existing research on Wikipedia is at the aggregate level, looking at total number of edits for an article, for example, or how many unique contributors participated in its creation," says Sudha Ram, professor of management information services.

"What was missing was an explanation for why some articles are of high quality and others are not. We investigated the relationship between collaboration and data quality."

Wikipedia has an internal quality rating system for entries, with featured articles at the top, followed by A, B, and C level entries. Ram and graduate student Jun Liu randomly collected 400 articles at each quality level and applied a data provenance model they had developed. "We used data mining techniques and identified various patterns of collaboration based on the provenance or, more specifically, who does what to Wikipedia articles," Ram explains. "These collaboration patterns either help increase quality or are detrimental to data quality."

Ram and Liu identified seven specific roles that Wikipedia contributors play. Starters, for instance, create sentences but seldom engage in other actions. Content justifiers create sentences and justify them with...