Can SUS be used in order to test the usability of a document?
Any guidelines will be much appreciated.
Both printed and digital documents can be evaluated for usability, in the sense that you can define metrics that gauge just how easy it is to use the document. There are also overlaps between the use of colour/contrast, typography and information architecture that are relevant, although you have to adjust it for the type of content, which is a static document rather than an interactive webpage.
To provide some guidelines, it would be good to know the type of document and the content involved, but here are some areas to look into further:
You can probably try to adapt the SUS to ask these types of questions if you want, but it might be easier also to just construct questions around these topics.
I wouldn't use it.
I'd use a test which was designed to measure "Readability"
There are a number of established tests of this
This covers the content of a document but not other aspects such as font, font size, and indexing.
SUS has been shown to work well with isolated parts of the system - i.e. you can re-define the "system" being surveyed as "the eBill".
However if the phrasing of a question causes significant doubt about a valid answer, then that is likely to skew the results. So take look at the questions individually
Given the above, if the eBill has interactivity I would run the standard SUS test with "eBill" given as the "the system" under review.
However if eBill is static then Q.5. would need a re-visit. e.g. "I found the various parts of the eBill were well integrated." Which could introduce a small variance to the scores. I would expect that most people would understand that a tweak that small will not impact results.
Likewise I would replace the text "system" with "eBill" throughout the questionnaire rather than just defining it upfront.
I'd recommend validating these tweaks with any reviewers before doing survey.