There are some other tagging suggestions mentioned in those threads that
you might want to add to your survey:
amenity=cram_school, amenity=tutoring, office=tutoring,
The last one, education=tutoring, is the best IMO but hinges upon the
general acceptance of education=* as a valid tagging scheme, which is
uncertain at this point.
Thank you for the information. My main idea is almost identical with what is presented in the last thread.
I have two reasons to express this idea in my diary.
1. OSM Japan community is not so aware of the current situation and issues of tagging educational institutions outside of school. I wrote a Japanese diary first to pose a problem to our community and asked the readers to give comments. https://www.openstreetmap.org/user/yumean1119/diary/364501
2. My goal is to organize tagging schemes on various types of educational institutions, not only on cram school or tutoring school. I have been worried about the slow progress in discussing a simple tagging scheme(education=*) https://wiki.openstreetmap.org/wiki/Proposed_Features/Education_Reform_Alternative and I felt the need to decide our policy on using education=* tags before we go to the next step.(e.g. deprecating amenity=school;university and so on)