What's an ideal method for sorting search facets?

Question

(I'll be the first to slap myself for asking for an "ideal" method -- I'm really looking for thoughts on how to think about this to make sure I'm considering the options for my specific scenario.)

Two keys to understanding the question:

1. Each filter is formatted with the number of results within that filter (i.e. Red [18]).
2. Some filters--Brand, for example--can come back with 1-200 unique filters. Each filter can only have a set number of facets (chosen by the importance of the filter) with a "See All"-style link at the bottom.

Given that, when the filters are written out, I've narrowed to three options for sorting & hiding:

1. Alphabetic with inserts.

   *Color*                     *Color*
   Green (9)                   Blue (5)
   Magenta (14)                Green (9)
   Purple (20)                 Magenta (14)
   Yellow (10)                 Purple (20)
   See All                     Red (1)
                               Yellow (10)
   

   This is my favorite. The entire list is alphabetic, but only the 4-5 "best" results are shown by default. When the "See All" link is clicked, the lower-rated facets are inserted in the correct alphabetic order.

   The biggest downside to this one is inserting items into the list. It'd be difficult to make sure this is noticeable.

2. Alphabetic with Append

   *Color*                     *Color*
   Green (9)                   Green (9)
   Magenta (14)                Magenta (14)
   Purple (20)                 Purple (20)
   Yellow (10)                 Yellow (10)
   See All                     Blue (5)
                               Red (1)
   

   This is just a shade different than #1--The items are listed alphabetically, with only the "top" filters (by count) showing. Clicking "See All" appends the final two filters. These two come in alphabetically, but the entire list is now more like two merged lists.

3. Count Sort

   *Color*                     *Color*
   Purple (20)                 Purple (20)
   Magenta (14)                Magenta (14)
   Yellow (10)                 Yellow (10)
   Green (9)                   Green (9)
   See All                     Blue (5)
                               Red (1)
   

   This sorts the filters by count. It removes the issues with #1 and #2 (namely breaking the sort order or inserting nodes), but seems the hardest to use by default. Having the items in some type of alphabetical sorting seems key to ease of use.

Would love any thoughts! Maybe I've just over thought it?

Answer 1

I prefer a slight adaptation to your second example, "Alphabetic with Append." My slight adaptation is to make a distinction between the top 5 and the remainder of the results. This could be something as simple as a horizontal rule below the top 5, or showing the results in columns to the right. For example:

    *Color*                     *Color*
    Green (9)                   Green (9)
    Magenta (14)                Magenta (14)
    Purple (20)                 Purple (20)
    Yellow (10)                 Yellow (10)
    See All                     --------------
                                Blue (5)
                                Red (1)

I don't like your first option, since the entire list updates. If the user is clicking "More," they are indicating that what they want is not in the top 5. They want to be shown everything else, and intermixing definitely-wrong results seems counter-productive.

Answer 2

You'll want to ask yourself, what should drive the sort order in your particular case?

• Is it availability/scarcity
• proximity to the user
• brand recognition
• some other factor?

The answer will depend on the user's reason for searching. Are they shopping for furniture? Looking for a job? Booking a flight? Searching for a recipe?

I see your #3 implemented often, and I suspect it is because I most often encounter faceted search when shopping for tangible products, and the key facet is brand name. Brand recognition helps to add meaning to the order to this type of list. If I see a lot of options for a particular brand, that tells me about the depth of their selection. If I see a lot of brand names, that is informative, too, about the breadth of selection at that particular store. Or, on the job search site, it tells me at a glance about the limited availability of UX jobs in Hawaii ;-)

Yesterday I did a search at major retail websites for mattresses. The retailers brought back facets starting with category at the top of the tree: "Kids', Memory Foam, Pillow Top", etc. Those were just presented as checkboxes to filter the search, and some websites included counts while some did not. The first facet that consistently displayed a count and the "more" or See All" option was Brand Name. It's easy to see at a glance that these retailers offered hundreds of mattress options from the top brands. I think this is more difficult to see meaning in your example where all colors names are equal, and you want to list them meaningfully. In the case of colors, sure, alphabetical makes sense. But when brand is a driver, the incremented count of options probably defines the sort.