Usability Benchmarking and Rating – choosing an approach and rating scale
I’m conducting some UX benchmarking activities and am trying to compare various approaches, both at the individual task level, and activity (multi-task, overview) level. I’m not well versed in the intricacies of the mathematics behind best practices regarding rating scales and would appreciate advice or perspectives on deciding rating scales. I’ll be combining expert reviews with user input too, and want to be intentful on what methods I choose.
My options: The simplest method I’m considering is 3 levels (poor/red/0, average/yellow/1 good, green/2), of course. Of course there is the classic Likert Scale at 5 levels (Strongly negative / 1, negative / 2, neutral / 3, positive / 4, strong positive 5). There are are many other rating systems (thumbs up and down), and 10 point rating systems, to name a few). How might I go about comparing them. I know that various questionnaires have various rating systems, so there must be best practices on choosing one, I’m assuming.
I’m looking for references or explanations on how I might go about thinking about the pros/cons of each - rating scale - I’ll be using different scales at different points, for different reasons, and want to be methodical and have reasoning for my choices. I know this is high level / abstract; I’m not looking for answers per se, but rather I’m seeking a way to help me think this through and criteria / concepts I could use to do so. I’d like to be more informed before I go to my colleagues with some ideas so I can frame the conversation effectively. Thoughts?