Structure and filtering of arxiv categories
We need to have a clear comprehension on how arxiv uses its categories:
- Which categories are subcategories of other categories?
- Can both a category and a subcategory be assigned to the same record?
- In which cases are subcategories (or even subsubcategories) used and when not?
When this structure is clear, we need to decide how we want our filters to work:
- For which categories should we provide filters?
- When n categories are selected, sample a random record from the union of all matching records, OR, sample a random record from a specific category with a chance of 1/n?