From here on meta, I see how to check the number of tag wikis I have edit. From my profile's reputation page, I see I have a few dozen approved wiki edits, for example on this page it shows I have done only 13 edits.
I also see no one has that badge on the main site. But it is on Stack Overflow, so I don't think it is a general problem.
Tag wiki excerpts do not count towards the badge, even though you get rep for them.
From here:
Research Assistant
- silver; awarded once
- Edit 50 different tag wiki bodies
- Edits to tag wiki excerpts do not count
- Source: badge announcement MSO post by waffles
For example, you have no edits on the tagwiki of soldering, but three edits on the excerpt.
