I have come to the opinion that Wikis are like highly fertile soil. Things grow in a wiki. But to make a beautiful garden requires a few things.
First, to make a beautiful garden on a plot of fertile soil requires a vision, a unifying plan of what the garden should be like. In our case, the unifying vision is the broad concept of an "encyclopedia" -- a distillation of all human knowledge.
Second, to make a beautiful garden on a plot of fertile soil requires gardeners who tend with loving care to each little corner, pulling weeds, training vines, planting seeds. In our case, the pulling of weeds and training of vines means editing some articles to make them constantly better. The planting of seeds involves making index pages that cry out for new growth to appear.
And finally -- to push the metaphor a bit too hard -- a wiki needs sunlight, which means that the active participants always talk in an open and sunny pleasant way about changes that are being made and disagreements that need to be resolved.
So be smart. But be civil.