I'm currently investigating the probability of introducing System Usability Scale (SUS) as a means of quantifying the comparison of new vs. old systems. The system in-question is like-for-like, and as such SUS appears to be an ideal means of gathering such user satisfaction ratings.
However, to get buy in from the wider project team I've been asked to validate my proposal, which is where I become stuck.
My immediate thought being to pull together a list of organisation names that employ SUS as part of their processes. Not necessarily the actual data, but a means of demonstrating that organisations of all shapes and sizes have used (and indeed make use of) SUS for the purpose of validation among other things.
The fact that SUS has been around for 30+ years requires justification on my part I'm afraid. And whilst I appreciate similar questions have been asked in the past, I've Googled aplenty but unable to pull anything of relevance against what I'm ideally looking for.
If anybody could point me in any kind of direction it would be highly appreciated.
As far as I know there are a few SUS studies (some say about 500 and original Brooke, J. (1986) paper just the first of them) proving it is reliable and very convenient (you can acquire reliable results form a very small sample) method of measuring user satisfaction and recommendation likelihood. But at the same time some studies suggest it is not a good predictor of actual usability Task-Performance metrics http://www.measuringu.com/papers/Sauro_Lewis_CHI2009.pdf
SUS is a useful 'blunt tool' that can be adapted for many situations. Nobody actually validates it, they just use it and then eventually drop it. As some studies have shown, it has an odd factorial structure in that 2 of the items are really about Learnability; the other 8 are general impression type items. Added to that, most people score quite high on SUS so you need large sample sizes (precision of measurement and sample size are inversely proportional). The good thing about SUS is that it's totally free and totally in your hands.
A psychometrically validated questionnaire that gets a lot of traction is SUMI (sumi.uxp.ie). It has a standardisation base and some extra features that enable you to get a handle on what's really bothering the users. (Disclaimer: it's MINE!) The bad thing about SUMI is that it costs money but then, hey, a lot of work went into it :)#