Professional communities

Scholars collectively develop expectations about what counts as good research.

For example:

Which questions are important?

A historical journal might repeatedly publish articles about colonialism but rarely about medieval taxation.

That influences what researchers perceive as worthwhile.

Which methods are respectable?

A discipline may strongly favor quantitative analysis while giving less attention to purely textual interpretation—or vice versa.

Which arguments deserve attention?

A new argument might be regarded as important if it engages major debates and evidence.

Another might be ignored because scholars regard its method as inadequate.

This is professional gatekeeping, but gatekeeping does not necessarily mean deliberate censorship.