Essentially, it depends on the context and the level of expertise of the user. For example, if you are in an e-commerce setting, and you are selling to the masses at the top level of your navigation, then less is definitely more. In terms of top level nav guidelines, most folks use the old 7+/- 2 rule from cognitive science (where 7 is the average number of things people can keep in their mind at any given time). Some sites get away with 10-12, but really, 6-7-8 is ideal in terms of scannability. As you scan across a number of choices, you have to evaluate them against each other, so having more than people can keep in mind at once means they have to go back and forth. User testing is the best way to gauge the right number.
Where it starts getting interesting is when you drill down in one facet and expose additional facets for refinement. Here the tolerance is lower in general, and only creeps up if you are an expert user with specialty needs. For example, if I’m an average shopper and I drill down into cameras on a website, then I might care to see facets for Brand, Price, Megapixels, Zoom... That’s starting to push it in terms of number of facets. 3 or 4 is usually the most you want to show fully (as Patrick mentioned)... But you can show additional facets for those expert users (e.g. photography enthusiasts), and just collapse them so that they don’t overwhelm everyone else. Only the hard core will ever go perusing in your lesser-known facets.
A similar pattern exists within the enterprise: you can usually get away with a handful of facets in a search refinement interface... Again, 3 or 4 – whatever fits above the fold typically. People won’t dig too deep if they are not expert users.
So to recap, 3 or 4 is usually the sweet spot for refinements...
You can give more for expert users as long as you use UI tricks to avoid overwhelming folks
7 +/- 2 is a good rule of thumb for navigational categories
Hello, I'm a master course student of UFRJ University, here in Brazil. I've been lurking here for a few days, and this is the first time I ask a question for ...
... Hi John, Yes, I agree it looked like a naive way to address this issue, but what I was trying to ask is: are there any general guidelines or good practices...
... Hi Renato - I'm sorry, I meant no offense - really, I shouldn't post late in the day. 19 is the number of dimensions in my framework and it seems to me...
... Hello again, Renato I recently joined this group for a couple of reasons: One is to find out where the taxonomy community is headed. Two is to find out...
The answer is it depends on what you want to use the facets for, and how simple/predictable they are. If you want to use facets for navigation, users typically...
Hi Renato, Patrick was right with his answer of "it depends" (a typical consultant answer that I swear by)... But of course you're looking for more :) I wrote...
... Renato, I would like you to reconsider the scope of your question. As practitioners, we have found that classification structures vary depending on the...
Having problems with message search?
Fill out this form to ensure your group is one of the first to be migrated to the new message search system.
Offline 
Send Email