One of many posts on my Readiness Assessment. As a reminder of the ground rules, I can’t ask for or get (intellectual) help. Cookies and emotional support are, however, welcome.

I think this is my last post about affordances for the night; after reading these two things I felt a sense of closure on the topic that was good-enough -- I'll be able to write through this skeleton of literature, fill it in with my ideas, fill it in with examples from various parts of the world I've seen, and then I will have an answer to the second part.

So, about those two things! What were they!

Well, I wanted to go back to my own first encounter with affordances, so I pulled out The Psychology of Everyday Things, a book my human factors and interface design course had used in undergrad. How had the idea been adapted? I mean, Gibson had said it would evolve, so I read Norman's book as another player's riff on Gibson's score as preparation for writing my own. (It's actually now called "The Design of Everyday Things," but the Purdue library had the older 1988 version, so that's what I'm drawing from here.)

Q 19: ...the term affordance refers tothe perceived and actual properties of the thing, primarily those fundamental properties that determine just how the thing could possibly be used.

P 19: Norman uses the phrase "is for" as a synonym for "affords" -- a chair affords sitting / a chair is for sitting.

This is helpful. Clearer than my own definition, which is more precise (perhaps) but also wordier, more awkward, more theoretical. The "is for" construct is particularly useful for me. I want my final output to be clear and readable by people who don't want to slog through theory.

P: Affordances provide strong clues to the operation of things. Plates are for pushing. Knobs are for turning. Slots are for inserting things into... the user knows what to do just by looking: no picture, label, or instruction is required.

N ^: This is a riff -- a difference, a flight off from Gibson's original definition of the word "affordance." Gibson's affordances aren't quite as active, they don't provide clues so much as they have properties perceived and then acted upon; Norman's notion of affordances is more communicative, less in the passive voice.

P 81-87: Constraints are partner to affordances; together, they help us figure out what to do with an object or in a situation. Using the example of an experiment where subjects were asked to assemble a Lego figure with no instructions (it turned out to be a police motorcycle), Norman talks about four types of constraints:

  • physical ("this peg can only fit in that hole" -- this is closest to the definition of an affordance)
  • semantic (relying on the meaning of the situation, like "the lego rider needs to face forward")
  • cultural (although the red light is physically constrained to 3 locations, on the lego figure, it is culturally constrained to one of those three location -- the back, as the stop-light)
  • logical ("the blue light could have fit 3 places as well, but cultural constaints helped us figure out that 2 other lights went in 2 of those spaces, so it must go in the last one")

Q 132: Forcing functions are a form of physical constraint: situations in which the actions are constrained so that failure at one stage prevents the next step from happening.

N ^: Is it possible to have cultural constraints cause a forcing function, instead of physical ones?

Q 161: There is no such thing as the average person... suppose you design a product for the 95th percentile, that is, for everone except the 5 percent of people who are smaller or larger. You're leaving out a lot of people. If the United States has 250 million people, 5 percent is 12.5 million. Even if you design for the 99th percentile you'll leave out 1 percent of the population -- 2.5 million.

P 162: Designers can accommodate variation (the "there is no average person" thing) by making things adjustable or by making special products for those who aren't served.

N ^: I could use this as an argument for access ("look at who we're missing!") but I could also -- and I think I would rather -- use this as a way to illustrate that tapping the long tail is sometimes a completely viable strategy. Are these crazy transparency ideas niche, only usable for a small number of people in a small number of circumstances? Sure, but that small number is pretty big. (On the other hand, I don't know if I want to use that argument -- it weakens the larger picture of my position, and I don't entirely believe it's necessarily niche. This is a defensive-type idea.)

Q 188: The principles of design are straightforward.

  1. Use both knowledge in the world and knowledge in the head.
  2. Simplify the structure of tasks.
  3. Make things visible: bridge the gulfs of Execution and Evaluation.
  4. Get the mappings right.
  5. Exploit the power of constraints, both natural and artificial.
  6. Design for error.
  7. When all else fails, standardize.

Q 204: (picture caption showing a door preventing special-needs children from opening it easily) The principles of usability espoused in [this book] can be followed in reverse to make difficult those tasks that ought to be difficult.

N^: "making things visible" echoes "making thinking visible," a key concept (and part of the title of a key paper) on cognitive apprenticeships, a big chunk of what I want to talk about in my lit review section for this RAT. (The acronym of the exam is a bit unfortunate, I think. It's also probably deliberate.) Also, I like the reversibility of the rules; I might play with that.

So much for Norman. And definitely a fond nolstagia for my undergrad days as I read it -- I was transported back to my teenage self playing with these ideas for the first time, working on my HFID project with Nick and Rob, sitting in the studio late at night for Team Gorgonzola.
Finally, I looked at a more recent review of Gibson's ideas (Scarantino 2003, "Affordances Explained") that claimed in its abstract to "give affordances a theoretical identity enriched by Gibson’s visionary insight, but independent of the most controversial claims of the Gibsonian movement." I hadn't realized there were controversial claims, or for that matter, a "Gibsonian movement," but that was probably getting further down the rabbit hole than I wanted to dive -- still, let me skim and see what's there.

Ah, okay -- a few helpful rephrasings and clarifications of things I already know, but still -- nice to see how others write about them.

The paper itself isn't that useful to me, though maybe I say that now because I'm tired. It's fascinating; it goes off into deeper analysis of the affordances idea -- but I don't need to go that far down the rabbit hole (I am tempted, but it's outside the scope of this paper, it's almost 1am, it's... I should stop.)

Okay. I'll grab a quote I actually really like, and then stop.

Q 954:  ...affordances are what they are independently of whether or not they are perceivable (some may not be), and independently of how they are eventually perceived (directly or indirectly).
That, to me, hits the concept with a lot more clarity than my jumbled version at the end of reading the first Gibson essay did. Thanks, Scarantino.

Right. So I was initially going to go read methods stuff for the rest of the night so that I can post that tomorrow, but it's nearly an hour past my hoped-for bedtime, so I am going to sleep. Tomorrow's posting goal is to write about both the methods I want to mention (grounded theory and narratives) as well as the question of validity and rigor. Reading and writing enough to get out those three posts. And on Friday -- well, but I'm getting ahead of myself. I'm thinking that Friday I'll start to tackle the first question in earnest (lit review) and also type out a full outline, but -- that really depends on what happens on Thursday. So let me sleep, and then let me see what tomorrow brings.

Holy shit I love doing this.