What is the purpose of the community wiki?

Question

There seem to be 2 conflicting ideas about community wiki Questions and answers:

They are low value questions:

• you don't earn any reputation for answering / editing
• they are difficult to find (more difficult to ordinary questions, there is no wiki tag)
• no mention of the community wiki at https://math.stackexchange.com/help
• Difficult to see why an question / Answer is awarded this status
• the questioner cannot mark what the right (or most complete) answer is
• maybe other reasons I haven't discovered

They are high value questions:

• you need a higher reputation to create or edit them.
• maybe other reasons i haven't discovered

It all seems a bit mixed up.

We should one clear answer to this question and then get the features that it deserves

So what is the purpose of community wiki?

I was planning to make some feature request about them , but i guess we first need to agree what their goal is, before we can come up with features that can improve their standing.

Answer 1

There are several answers to this question, there is the original purpose of the community wiki feature, there is the common "misuse" for its reputation denial side effect, and the purpose and utility depend heavily on whether it is a question or an answer that is made CW.

Community wiki was created when the feature of suggested edits did not exist yet. Making it possible for many more users to edit the post was the primary purpose, this effect doesn't matter much since everyone can suggest edits. What is left of this is that making a post CW indicates that the author wants other users to edit the post substantially. Drastic edits to a non-CW post are likely rejected or rolled back, for a CW post such edits would be explicitly encouraged.

The other main use of CW for questions is a "misuse" of the feature. Soft questions are often marked as such to prevent the users from gaining reputation for a question where the upvotes don't necessarily indicate knowledge or competence. This used to be very common across the entire network, but most sites have now simply declared such questions off-topic and avoid the whole issue this way. MSE is one of the rare exceptions here.