Where facets fail

[Why facets suck at #1: Providing narrative.]

• 1. Slicing and dicing is great, but... the constant reorientation can be confusing in and of itself: Most people are bad at spatial reorientation and if you think of each facet as a dimension of the data, everchanging rearrangements of facets can be similarly jarring.
• The following is the kind of drawing you might do in a high school drafting class. It is a 3-dimensional cube represented as a series of 2-dimensional drawings, showing all faces of the cubes. Takes a second to put it all together into a cube, doesn't it?
• 3D.png:
  
• Can you tell when the image has made 1 revolution?
• The following image has been taken from: http://synapses.mcg.edu/anatomy/astro3d/astro/A_3D.stm
• 3-D_rotating.gif:
  

• 2. Faceted systems don't quite tell a story
• To be fair you have the same multi-level chunking that you get in well-designed hierarchies:
  • Chunking of items into containers and then
  • Further chunking of containers into container types (facets)
• And the chunking is far easier to maintain because the containers and container types are NOT locked into a fixed parent-child structure, but instead co-exist independently
• Similar to well-designed hierarchy levels, a well-designed facet that is filled out end-to-end with minimal overlap can greatly enhance the browsing experience.

However, it is precisely this lack of structure that also means that Faceted systems *don't prioritize" the container types for you the way Hierarchies do and as a result, they fail to go that final mile so crucial to storytelling: a linear dictation of what order to experience the facets in. Instead Faceted systems are designed to allow the user to construct their own storyline.

• Case study: iTunes
  • First, you might figure out that the kind of data you are dealing with is songs, because the facets are: Artists, Albums, Genre, Composer
  • Second, by looking at the range of Containers or Attribute values in each Facet or Attribute, you get a sense of what what kinds of songs you have: Bob Dylan v. Berlin Philharmonic v. Kenny G
• But ultimately, facets fail to give you a sense of the facet foodchain, which a hierarchy of Genre>>Composer>>Artist>>Album does:
  • That Genre is a bigger, more everlasting concept that a Composer, which is inherently an individual person, living in a particular time.
  • And Composer, especially in Classical music is a bigger, more everlasting figure than any individual artist that performs and interprets the work of that Composer. (ie. An analogy might be how certain bureaucrats outlive the elected presidential administrations they serve: Henry Kissinger)
  • And finally Artist, assuming they have more that 1 hit song, is a more everlasting thing than the Albums they release.

• Case study: DDC
  • Compare Area of study>>Region>>Time period to (where Area of study, ie Philosophy, transcends all physical boundaries and exists throughout time and Region transcends Time) to
  • Area of study
  • Region
  • Time period

[Facets don't always work for #2: Guided navigation to explore a particular topic.]

• 3. It's not always clear how best to use Facets
• The lack of a fixed structure also means that users are left to construct the right structure for the right task, which is maybe not what some people are interested in doing. A well designed faceted system should perhaps provide users with options based on what they want to accomplish, rather than asking them to construct a Faceted browser one facet at a time. (ie. How many times have you watched an inexperience computer user search on Google using some incredibly generic term.)
  • If you want to get dressed, the system presents you with the Closet hierarchy
  • If you want to do your laundry the system reorganizes into the Laundry hierarchy

• 4. Facets have to be added one at a time
• Hierarchies provide easy affordances for attaching semantics to data because the entire organizational structure is visualized
• Facets, because they're independent of each other, must be added one at a time (ie. filling out the fields of a form)
• Caeat 1: We believe is primarily a workflow structure and interaction design challenge that can be overcome
• Caveat 2: This obviously doesn't apply to automatically derived metadata (ie. CDDB)
• 02_Hierarchy_Encoded_Space.png:
  

• 5. Hard to design facets well
• A well designed facet, just like a well-designed semantically encoded level of hierarchy:
  1. Fills out the spectrum of the facet from end-to-end (ie. Beginning to End: Planning, Execution, Documentation, Post-mortem) so you're never afraid you're missing something.
  2. Has no overlaps, so you're never ambiguous about where something belongs.
• Katie has a project called 0.6 planning, but does it really belong in the Project facet? Or is there more to this story?
  • Release: 0.6
  • Phase: Planning
  • Product layer: i18n
• It's hard and tedious to design facets with no overlaps

As a result, just as Hierarchies turn into chaos, Faceted systems often disintegrate into Tagsonomies