imagine you have a group of children and want to give them lunch. In the UK you might well choose baked beans. Not the most exciting choice, but few children actively dislike baked beans; they are acceptable to everyone. However, give each of those children a euro (or maybe two) in a sweet shop … they will all come away with a different chocolate bar, the chocolate bar that is ‘OK’ for everyone gets chosen by none. Much of traditional HCI design is like baked beans – a word processor installed for the whole company, a mail program used by every student, good enough for everyone. However, increasing personal choice, especially for web-based services, makes design more like the chocolate bar; different people make different choices, but what matters is that the product chosen is not ’good enough’ for all of them, but best for some.
Now I’ve covered this in my 2007 paper discussion  and Dix has a very good point. I think that the salient point here is that systems run in a combinatorial way, where as individual findings can exist with minimal confounding variables muddying the waters.
Different operating modalities are useful for providing a personalised experience and a one-size fits all approach is not the way forward. Indeed, I wonder if universal design, or participatory design just encourage a product which is acceptable to all but desired by none.
- Dix, A. (2010). Human–computer interaction: A stable discipline, a nascent science, and the growth of the long tail Interacting with Computers, 22 (1), 13-27 DOI: 10.1016/j.intcom.2009.11.007
- Simon Harper (2007). Is There Design-For-All? Universal Access in the Information Society, 6 (1), 111-113 : http://dx.doi.org/10.1007/s10209-007-0071-2