Re: [xml-dev] "Introducing MicroXML, Part 1: Explore the basic principle

[Norman Gray <norman@astro.gla.ac.uk>]

Greetings.

On 2012 Jul 6, at 10:26, Michael Kay wrote:

>> .   The term “affordances” is interesting but I can’t seem to figure out what it really means
> 
> I think it's mainly interesting as an example of a social phenomenon whereby the enlightened invent specialist vocabulary explicitly to prevent the unenlightened joining the conversation.

[I only read the quoted message briefly, and can't retrieve it, so I may be misremembering the context; that said...]

I think this is a tad unfair, Michael.  The term 'affordances' has a perfectly respectable lineage in the terminology of user-interface design, and (a more important consideration) labels a useful notion which is hard to think with until it's thus pointed out.  I'd go as far as to say that anyone with a passing interest in usable software should be at least broadly familiar with the notion.

Roughly (and as I understand it), the affordances of an object (be it physical, on a screen or, at a stretch, an API) are the actions which the thing suggests to the user as possibilities.  If a door opens only one way, for example, then it's useful to have an obviously pullable handle on one side and an obviously pushable plate or knob on the other, so that when walking up to the door you 'know' what to do with it without thinking or being told.  If it has 'pullable' affordances on the push-only side, it's arguably badly designed.  The extension to computer GUIs is obvious.

The wikipedia page <http://en.wikipedia.org/wiki/Affordances> makes the notion sound more exotic than it really is.  Donald Norman's 'The Psychology/Design of Everyday Things' (which is where I first saw the term) is a good book about industrial design in general, and not just GUIs.

Best wishes,

Norman


-- 
Norman Gray  :  http://nxg.me.uk
SUPA School of Physics and Astronomy, University of Glasgow, UK