What tag to use for questions asking for studies? Currently we have "research", "evidence" and even "science"

Question

We have 8 questions tagged research.

We have 6 questions tagged evidence.

We have 9 questions tagged science.

None of these tags has a tag wiki excerpt.

Both, research and evidence seem to be clear tag synonyms.

With science it's different as this has a legitimate use teaching kids science concepts etc. But it has been used in the same meaning as reserach and evidence in one question before (that's also tagged evidence), so I didn't want to leave it unmentioned. It probably only needs to be retagged.

Since tags are used to filter questions accordingly, having only one tag at maximum improves user experience.

Now, I see the following possible and sensible options:

1. We keep research (and science in its original meaning). evidence becomes a tag synonym of research.
2. We keep evidence (and science in its original meaning). research becomes a tag synonym of evidence.
3. We expand science to also include asking for research and both, research and evidence become tag synonyms of science
4. We declare these research and evidence to be meta tags and get rid of them entirely.

Which option do you like most or did I overlook one?

Answer 1

Personally, I like your first option:

We keep research (and science in its original meaning). evidence becomes a tag synonym of research.

It seems to me that evidence implies research that supports a [behavior/other], whereas research is more open-ended as to conclusions, if any.