Back in the late 80’s, Apple Human Interface concluded that the mouse is faster than the keyboard, objectively. But also that every test person subjectively thought that the keyboard was faster.
Quote from the book “Tog on Interface”, by Bruce Tognazzini (originaly published as an article at asktog.com):
We’ve done a cool $50 million of R & D on the Apple Human Interface.
We discovered, among other things, two pertinent facts:
- Test subjects consistently report that keyboarding is faster than mousing.
- The stopwatch consistently proves mousing is faster than keyboarding.
This has caused many arguments and discussions (eg: by Jeff Atwood and at skeptics.SE, but all of these are based on subjective assumptions.
So, I’m looking for some other, newer studies that could either verify or refute those findings from the 80’s. Are there any recent studies on the “Keyboard vs Mouse”-issue?
I’m concerned about two aspects:
- The time aspect. Performance vs preference.
- The workload aspect. What’s the learning curve like? How many shortcuts does the novice user use, and how many shortcuts are the experienced user able to handle?
I don’t doubt that keyboard shortcuts are faster is many situations, but I would like to see some more research on the issue. Conducting one myself isn’t an option (and it would be unnecessary if it’s already done). Subjective opinions and referral to “the obvious” won’t give me the answers I’m searching either.
KLM/GOMS/MHP are all good models that could function as a theoretical basis to explain what’s happening. Any reference to any such work on this area would be good too…
So why am I asking about this?
Well, as a UX professional, I would like to base my stack of knowledge on research, not assumptions. IMHO, the fundamentals of UX are based on “find out, don’t assume”.
It can be difficult to convince people about the UX-work. Having proper research is one of the most important tools we have. (Letting them observe users use their software is the most important one).
But it is so obvious!…
No it isn’t. When users are confronted with multiple design options, the correlation between preference and performance is very low. Only 25% would prefer the solution with the best performance.
We also know that heavy mental workload makes you think that you’re effective, even if you’re not (just like the Apple research concluded). So the feeling “this is the fastest solution” doesn’t actually make it the fastest solution.
Why is it important to know this? Just provide both, and let the users choose!
Well, if I’m going to train a user group, I would want to base my advises on something. Right now, the only research I can base my advice on says “Minimize the use of shortcuts. You’ll just fool yourself and believe you’re faster than you actually are.”
Some of the specific issues I’m looking for in the research:
- What’s our capability to remember shortcuts (number of shortcuts, decay rate, etc). The general MHP-research actually says something about this.
- Performance differences. (Something can be worked out from the KLM/GOMS theories.)
- What is the performance improvement for the shortcuts you remember immediately.
- What is the performance loss (if any) in the situations where you have to “think twice” to remember a shortcut.
- What is the “recovery cost” in the situations where you use the wrong shortcut (or didn’t remember it after thinking twice).
- Will the mental workload of “remembering” a shortcut affect the main work task? Say you’re doing accounting and need to handle 5-7 “chunks” of information already.
- Are there any thresholds you can use to say: “Just use N number of keyboard shortcuts and stick to the mouse+toolbar for the other commands.”
- What would the capability/advice be for each of these cells:
I know these questions are very specific, and that’s why I kept the question general in the first place.
Remember: I’m just asking for references to any research, I’m not asking for a winner or a conclusion, nor am I asking for specific answers to the issues I’ve raised in the “update” section above. This question is answerable…