Marco Arment on UI stability

In ATP Episode 439 Marco Arment had a good speech on UI stability, I even took time to write it down. It starts at 35:07:

UIs so often lack stability. It is such a critical quality. You want the UI to be stable.

Not every surface should be “live”... If you try to select some text on a website with a mouse on a desktop, you don’t want every single thing that you can click on or accidentally brush against with your finger on a phone to be something that is live, that does something. You want stability, you want things to feel solid, and predictable, and forgiving. And not being so susceptible to things like accidental input or imprecision in input... People are doing things unintentionally.

You also don’t want the UI to be moving around when people are trying to use it. And I feel like a lot of the current Mac design language these days, where everything is being hidden behind hover states and then things animate somewhere out of the way and change where they are... this is all violations of UI stability. It makes everything a hot zone or a live zone. And things are jumping around, and it’s disorienting, and it’s inefficient, and it’s unintuitive as well, and undiscoverable and all sorts of other problems.

Anything you can do to make a UI more stable in a sense that things don’t move around too much, there aren’t too many different modes where things come in and out or slide around, or pop in, or pop out, that makes it easier and better and more calm to use for more people. And it’s a better design.