Reservoir Hill writes "The Guardian reports that a study by Ed H Chi demonstrates that the character of Wikipedia has changed significantly since Wikipedia's first burst of activity between 2004 and 2007. While the encyclopedia is still growing overall, the number of articles being added has reduced from an average of 2,200 a day in July 2007 to around 1,300 today while at the same time, the base of highly active editors has remained more or less static. Chi's team discovered that the way the site operates had changed significantly from the early days, when it ran an open-door policy that allowed in anyone with the time and energy to dedicate to the project. Today, they discovered, a stable group of high-level editors has become increasingly responsible for controlling the encyclopedia, while casual contributors and editors are falling away. 'We found that if you were an elite editor, the chance of your edit being reverted was something in the order of 1% — and that's been very consistent over time from around 2003 or 2004,' says Chi. 'For editors that make between two and nine edits a month, the percentage of their edits being reverted had gone from 5% in 2004 all the way up to about 15% by October 2008. And the 'onesies' — people who only make one edit a month — their edits are now being reverted at a 25% rate.' While Chi points out that this does not necessarily imply causation, he suggests it is concrete evidence to back up what many people have been saying: that it is increasingly difficult to enjoy contributing to Wikipedia unless you are part of the site's inner core of editors. Wikipedia's growth pattern suggests that it is becoming like a community where resources have started to run out. 'As you run out of food, people start competing for that food, and that results in a slowdown in population growth and means that the stronger, more well-adapted part of the population starts to have more power.'"