> That being said, I don't think every website or tool needs to aim for the lowest common denominator.

Any application that will be used occasionally with the goal of not using it as quickly as possible should work this way.

A counterexample would be e.g. retail POS software, which should be optimized for minimum work and maximum responsiveness for trained users.

Huh? "The user is drunk" as a rule is great, there's no need to redefine it. Especially for POS interfaces! You'd want them as intuitive as it gets, because their users can be under a lot of stress, and could, in fact, be drunk.

I understand GP's "I don't think every website or tool needs to aim for the lowest common denominator" in two ways:

1. This rule isn't an excuse to stop raising the bar when it comes to interaction design ("drunk people won't notice the difference anyway").

2. Some machines should only be operated when absolutely sober and the interface should reflect that requirement ("don't drink and drive!").

Maybe things have changed in the past two decades, but I definitely would have been fired from my retail job if I showed up drunk. The POS interface there was super non-intuitive, but very efficient. This was 20 years ago so the classic text-mode interface with F1-F12 keys assigned to different functions.

While I doubt there's a single job where it'd be allowed to show up drunk, I also happen to know several bar owners that like to share some drinks with their customers. As required by law here in Austria, also bars need to use a POS system. I worked on one almost 10 years ago.

> You'd want them as intuitive as it gets [...]

I've recently been reading up on the science of learning, and I realized I never considered what intuition meant to me. Merriam-Webster lists it as:

> a: the power or faculty of attaining to direct knowledge or cognition without evident rational thought and inference

> b: immediate apprehension or cognition

> c: knowledge or conviction gained by intuition

If I could frame the thought of my original comment in terms of intuition, it would be:

All software should be intuitive, at what point that intuition is built differs.

For widest adoption, that software should be immediately intuitive to the widest group of people.

For maximum efficiency in a given (usually professional) domain, that software should allow a user who has built up their intuition to effectively merge with the machine.

I don't think one precludes the other, and a lot of the best software is immediately understood by a common user while having features for power-users. I do think there's a tradeoff to some degree though. If you're building a very specific technical tool, perhaps you can assume the user is a drunk programmer, but not a drunk grandmother. As in, the expected level of intuition need not be at the lowest common denominator.