[wp-hackers] hierarchical custom taxonomies vs good & old cats.

[Otto]

On Fri, Dec 17, 2010 at 9:54 PM, Haluk Karamete <halukkaramete at gmail.com> wrote:
> By alllowing tags a hierarchy of their own, and a context of their
> own, I achieve the best of both worlds.

But.. what exactly do you get out of that? Why would you want tags to
be in a hierarchy? That doesn't make any real sense to me.

Hierarchical taxonomies are generally used for very well-defined broad
sets of things. Categories, basically. The point being that often
these categories are predefined and you are simply picking them from a
list.

What you're talking about is essentially allowing tags to have
hierarchy, and I get that. I can even visualize a UI to do it. But I
still don't see the point of it. What is the purpose? What is it that
fundamentally changes by having tags in a hierarchy, exactly?


> I see no advantage gain by setting a custom taxonomy hierarchical. I
> already got that with good old cats.

Do you see any advantage in making a custom taxonomy non-hierarchical?
Why is that? I mean, after all, you can already get that with good old
tags...

You're looking at it from the wrong angle. Custom taxonomies are there
to allow you to create groups of related terms. How you create those
groups, whether they be on-the-fly poorly defined sets of terms or
well-defined sets of hierarchically structured terms, is irrelevant to
the purpose of having them be custom in the first place. They're
custom because you want to be able to group related terms together
into sets. A taxonomy is a set. That's it. How you arrange that and
define that set is up to you.

What I'm really asking is why do you want taglike-taxonomies to be
capable of having hierarchy? What does having hierarchy on a tag-like
set give you the ability to do that you don't have now?

Giving tags hierarchy makes no sense. Tags are created on the fly, by
definition they don't need hierarchy because they are not well-defined
sets of terms to put into hierarchical structures. Hierarchical
structures by nature assume advance planning and definitions being
created for them.

For your even/odd example, you should use two taxonomies. Even and
odd, both tag-like. Because having the even/odd categories which hold
number terms doesn't make any real sense. It doesn't give you
anything. You can't *do* anything special with that structure.

-Otto