The simple answer to my question is that "WikiTree users do!"
Let's talk about this a little further though.
You've written a biography for a profile and now you want to add categories in order to group the person. Well, where to start?
First, you should check our category system to see if something similar is already set up. Yes, this means some work on your part. Open another tab or window and start at the top. If you're looking for a place category, start at Find>Categories. Scroll down and click Category:Regions and drill down until you are in the area you are searching. Use your best estimation of where the particular category might be found and look around. Yes, this takes some time. If you are in a hurry, a quicker way is to use the category picker by clicking the button while you are in edit mode of the profile.(there is a picture in this section of the help.) Just begin typing a possible category name into the box and choices will begin to appear. You may have to try a few iterations of the name you are looking for. Nothing shows up? Now try to add it yourself.
Just follow the naming scheme you've seen used when you were poking around in the search you just did.
Save the profile. You'll get the red warning about the category not existing, but click save anyway.
Guess what? You're not done! There is a red link on the profile because the category does not exist in the category hierarchy yet; it needs to be tagged with a parent category.
I know what you're thinking. Category people will get this. Yes, we will...eventually. But what you are doing by leaving it red is leaving it for another WikiTree member to research. This member (many times ME) may not be as familiar with the topic as you are or may be busy doing other category things and may not get to the red category right away. Emails might need to be exchanged. So, it sits there and your profiled person is not a member of the group you want him/her to be part of. I am asking you kindly to do the research and figure out where your new category goes. If you struggle with it, ask here in G2G, tagged with "categorization." Someone will see it and answer (might take up to a day or so to get an answer, depending on work load.)
Maybe you discover that simply adding text to the "red" category will make the link go green. Yes, this is true. But it still has no parent category and is not a part of the category hierarchy until you do. A category person (again, me much of the time) must still do the research and complete the task.
Now, should you create a category for something super-specific? Depends. We don't need to group "Biologists with Green Eyes" or anything like that. Maybe you want a list like that for your own purposes? Personal category! Just make it [[Category:Smith-1234 Green-Eyed Biologists]] and add the parent category of [[Category:Smith-1234]], assuming you are Smith-1234 at WikiTree.
If you want a category that would be useful for grouping profiles that other WikiTreers might use, stop and ask yourself how many people might possibly use this. We had this discussion yesterday and I am still not convinced that sexologist needs to be a category because there are simply not that many people to add at this point in time in order to have a grouping of profiles. I did a quick search of WT and found one additional profile mentioning sexologist or sexology. Does grouping two people really justify a category? In this case, it's better to use something more general and do the detailing in the biography. (and add the sources!)
Oh yes, categories are here to group profiles. They are not biographies and they are not decorations. They should stem from what you have written in the biography of the profile. I should not add [[Category:Dentist]] to a profile that has no mention of dentistry, teeth, dental schools, etc.
If you start adding new categories that might be related and in need of a structure (aka a hierarchy) you should STOP RIGHT THERE and who ya gonna call? No, not Ghostbusters. You should get in touch with the Categorization Project. If you're working within the scope of a WikiTree project, you can work with that project and/or Categorization (via a category liaison). If you're on your own and have ideas about a structure, hunt us down. Ask in G2G or send a leader a PM or leave a message on one of our profiles. Structures need to be fleshed out and set up so that they can be used by all with ease and a minimum of fuss. A bit of collaboration will go a long way to prevent misunderstandings or misinterpretations of the help pages and guidelines. Procedures are here: [https://www.wikitree.com/wiki/Project:Categorization/Procedures].
You can even join us in the project, but be please be ready to work on maintaining the category system by correcting category errors. We are responsible for more than adding categories to profiles. At the moment, we have 102,491 errors, and categories are used on 1,343,550 profiles.
Now, I have one last thing about creating categories. We want you all to add them. Sure, with all of this nit-picky stuff I just said, it probably sounds like we don't. Nope, we want them; we just want them added as correctly as possible so that we can all find them and use them. :-)
EDIT: A wee note about personal categories. They are for WikiTree users only. Do NOT create a personal category for a WikiID of a dead person.
