Categories - Intertwingled: Information Changes Everything - page 39

Figure 2-15. Polar bears by topic and format.
The moral of this story is important. Due to the weakness of words, it's hard for any label at the
top of any taxonomy to stand on its own. We need the root categories of main navigation so
users understand the full scope, and so there's a place for all content, now and in the future.
Breadth lets the system scale over time. But the top taxon is too abstract for users and the bottom
too specific. The action is in the middle. So we must surface sample subcategories. Instead of
burying them under Topic, we should bring out the Polar Bear Cubs.
We must reveal what cognitive scientists call “basic level categories.” xxxvi In a taxonomy, the ba-
sic level is the largest class of which we can easily form a concrete image. It's hard to imagine
furniture, but we can all picture a chair. Few people use “pinniped” or can distinguish harp
from harbor, but like polar bears, we know a seal when we see one. At the basic level, we use the
simple names of folk taxonomy rather than the terminology of scientific classification. They are
the first categories that kids understand and have the most cultural significance for adults. Due
to the idiosyncrasies of human psychology and perception, they are optimal for learning, recog-
nition, memory, and knowledge organization. They are artifacts of embodied cognition and vital
tools for design.
So far, in talking taxonomy, we've been dancing around a central point. Since every classifica-
tion is flawed, we should usually use more than one. It's a simple idea that's hard to accept.
We're hardwired to believe there's one right way to organize things. Dewey's classification is a
monument to that spirit. But we are getting better at providing multiple maps and paths, and
it's helping our users enormously. In universities, for instance, we've learned to complement the
main navigation menu with alternate pathways such as audience, school, task, an A-Z index,
and search.
Figure 2-16. Universities offer multiple pathways.
And in e-commerce, faceted navigation is nearly ubiquitous. In the 1990s, when we began talk-
ing about facets and Shiyali Ramamrita Ranganathan, each online store had a single taxonomy,
and nobody knew who he was. They still don't, but we're all indebted to the mathematician and
librarian from India who realized that a single taxonomy isn't nearly enough.