Awiki is a type of online reference tool that allows internet users to update and change its content.  while a wiki can be a useful source of information, why is a wiki often an unreliable tool to use to expand your vocabulary?

A wiki might be considered an unreliable source because many users collaborate modifying the content and structure directly. This would mean that anyone can contribute and they might write false information, or opinions. If you need to expand vocabulary or research for information it is better to consult books or articles written and corrected  by professionals.