Monday, January 31, 2011

Is this Table Meaningless?

Maybe Andrew should take TSRM to task for this meaningless list of "affordances".


  1. Maybe I should. What's grabable depends entirely on who's doing the grabbing.

  2. Actually, I had a minute so I looked: it's ok, TSRM are paying attention:

    Table 1 gives a sample of affordances and effectivities together with the activity that they complicate.

    (Is complicate the right technical term here, or did Turvey make up another word?)

    They've remembered to include the effectivity, and although it's a little generic it's next to a section that lays it out quite clearly:

    A propertied thing X (e.g., a crevice) affords an activity Y (e.g., crawling into) for a propertied thing Z (e.g., a lizard) if and only if certain properties of X (e.g., the spatial extent of the crevice in the horizontal dimension) are dually complemented by certain properties of Z (e.g., the substantial width of the lizard in the horizontal dimension), where dual complementation of properties translates approximately as properties that are related by a symmetrical transformation or duality T such that: T(P1)-> P2 and T(P2) -> P1

    So I take it back; they're good.

  3. Of course, when you look at context that fills things in. That's how ellipsis works.

  4. This isn't about my ability to figure out what you mean; this is about asking the right question.

    Let me try this another way: if you showed a picture of some salt and asked 'is this soluble?', the correct answer would be 'er, well, it depends'. The question doesn't really make sense: you have to ask 'is this soluble in water?' or similar: you need the other half of the dispositional pair.

    My point has only ever been that the question 'is this edible' doesn't make sense. You have to ask 'is this edible by a human>', because only then can you run the right experiments to establish if humans try to eat it when it's present, and you can ask sensible questions about what the information might be, etc etc. In other words, this is what you have to do in order to be talking about affordances in a meaningful way.

  5. "Is this edible?" makes perfect sense to everyone. In this context, it is elliptical for "is this edible for humans?"

    At least now this irrelevant detail is off the main line of posts.

  6. A photograph of salt is not edible.