If one tag is a subcategory of another, should it be tagged as a synonym?

Question

For example, I proposed behavioral-psychology (with only one post tagged) as a synonym of the much more common psychology (87 posts), but now I'm not so certain I should have because there's also the tag cognitive-psychology with one post.

There appear to be two main ways of dealing with synonyms (aside from manual retagging).

One option would to be create synonyms pointing both cognitive-psychology and behavioral-psychology to psychology.

Advantages

• Users can search for the common tag of psychology and find all related tags.
• Questions that involve multiple subfields of the large tag (psychology) would just need one tag to annotate that (psychological) aspect.

Disadvantages

• If there get to be too many posts with the large tag, it could become difficult to find what you're looking for if you want to look at posts only on behavioral psychology.

Another option would be to leave both tags on their own so that they might eventually get more posts over time. The advantages and disadvantages for searching are similar to the above (reversed), but there are also changes in tagging behavior to consider:

Advantages

• Users searching for one of the smaller tags could find related posts quickly.

Disadvantages

• Users searching for one of the smaller tags would miss several related posts that had only been given the larger tag (psychology).
• Users trying to tag a new question would likely often tag it with semi-duplicate tags, such as psychology and cognitive-psychology together because psychology is more common, but cognitive-psychology is more precise.

If a tag is a hyponym (subcategory) of another tag, should it be tagged as a synonym of that tag? When? Why? or why not?

Answer 1

Generally? No.

It may increase the ability to find information, but it will also lead to an increase of non-relevant information. The internet is designed for interlinking, not overlapping - and I think that applies to your question.

In your example, you propose that behavioural psychology and cognitive psychology could be synonomized (is that a word?) with psychology.

As you explained, looking for general "psychology" topics, will return a great result! I only need one tag. The disadvantage is that when I look for information on classical conditioning (a fundamental concept of behavioural psychology), I encounter arguments related to constructivism, socio-cultural development, neurochemistry ...

So, rather than discuss the advantages (and disadvantages) of information categorization (and tagging vs. directories, etc), I'd suggest that the medium of interaction will suggest the optimal way of categorizing information.

For a small bookshelf at home? Have a psychology section. It's all related, and it's relatively small. For a public library, sub-divide the sections by author, theoretical background, or whatever is physically possible and logical.

I'm not sure that the internet (as a general concept, as well as the stackexchange Q&As) has the constraints that are fundamental to your argument.