http://www.liquidelearning.com/2007/06/waterfall-bad-washing-machine-g
I just came across this well-received post and presentation by Leisa Reichelt, who is a User Experience Consultant (someone who creates customer experiences that are both pleasurable and effective).She's an advocate of a non-linear, user-centred approach to design and build of anything from a retail space or a phone call, to a website.
She's posted a presentation which explains the pros of the washing machine approach (an iterative design process) versus the cons of a traditional 'waterfall' approach (used often in advertising, broadcasting, and much corporate e-learning solutions) where the design and build cycle follow a strict and linear process of
SCOPE
DESIGN
BUILD
TEST
Although I'm not convinced by the washing machine metaphor*, the presentation is worth a watch for an compare/contrast between the two design styles.
*in my experience, you open a washing machine, put stuff in, click on and leave it until it's finished...not much scope for opening it halfway and adding another pair of jeans or switching cycles...
Keywords: e-learning, language language, web 2.0
