A page designated for “practice” editing. This seems like a good idea, but may inadvertently hinder adoption. It diverts attention from pages containing real content, can makes non-early-adopters afraid to edit anything outside the sandbox, and gives the impression that a wiki has a steep learning curve.
How do I notice it?
Look for a page with the title “Sandbox” or something similar, or a description telling people to use it as a place to practice wiki editing. Or you might notice if users have very limited permissions by default, and only get permission to edit more content once they have “graduated” and proven themselves worthy.
How do I fix it?
Use the associated comments or discussion section of the page to propose deleting it, and gently encourage people to directly edit pages containing real content. Since edits can be changed as often as needed, and mistakes easily fixed, there is little risk in encouraging people to work directly with the information on the wiki.