Hugh Pickens writes: "New research shows that Wikipedia's ascendancy to the top of a large pool of online reference sites has come to an end as growth has leveled and the nature of the community has made it less welcoming to new contributors. "It's easy to say that Wikipedia will always be here," says Dr. Ed Chi, a senior scientist at the Palo Alto Research Center. "This research shows that is not a given." While the site is still wildly popular for those trying to figure out who played in Super Bowl XXII, the name of Pink Floyd's original frontman, or how a convection oven works, the explosive growth that characterized its early years leveled in 2006 at around 60,000 new articles per month, declining by nearly a third since then. But the trends within the community itself are far more troublesome. The year after the amount of new content flattened, the number of edits per month plateaued as well at around 5.5 million. Meanwhile, the number of users making edits leveled off at around 750,000 monthly. Data also suggests the Wikipedia community is becoming resistant to new content and new editors with passive editors who make just a single change per month seeing around a quarter of their changes erased or modified by other, more active editors. "This is evidence of growing resistance from the Wikipedia community to new content," says Chi. The resulting exclusion of more varied contributions shifts the balance of power on Wikipedia to those fewer active editors, and in turn could make Wikipedia more like a fraternity than a community-driven social encyclopedia. Wikipedia's growth "is consistent with a growth processes that hits a constraint — for instance, due to resource limitations in systems," writes Chi. "Rather than exponential growth, such systems display logistic growth.""