Thread by @dermdaly

Ok. I'm gonna expand. It's a thread. Bear with. We have a client app. It has a tabbed interface. We got the following feedback from a customer: "App is hard to navigate. Wouldn't let me go from <tab4> back to the <tab3> page without it shutting down". And so begun a (1/n)

..minor voyage of discovery.
I started with our Android guy who wrote it. Straight off the bat he said "There's nothing on the back stack, so pressing back is instructing the phone to go back from where it came" (i.e. the home screen). (2/n)

The developer in question knows his stuff. So, I trust him, but I also have a relatively new Samsung test device on my desk. Let's take a look shall we? I've installed very little, so it's kinda "out of the box" (3/n)

There's even a "Google" collection of Apps. Google. They'll know their UI, they invented it after all. So, let's try:
1. I open the Google Play App.
2. I select tab 2, then tab 3, then hit back.
The app navigated back to 2. I hit back again, it goes back to 1. (4/n)

I hit back one more time and the app quits and I'm back on the home screen. Has our dev got it wrong?
Let's try YouTube.
1. Select tab 2, then tab 3. Then hit back.
2. The app navigates back to tab 1 (wait what?)
Press back again, it quits and I'm back on the home screen. (5/n)

..This is not the same as Google Play. Better find another one. Let's try Google Drive.
1. Select tab 2, then tab 3. Then hit back.
2. The app quits, and I'm back on the home screen.
OK. We're up to 3 different interactions.
Better find another example (6/n)

Google Play TV & Music? Acts just like Drive.
Google Search App? It's goes with the YouTube method
Gmail? YouTube Method
YouTube Music? Surely will act like YouTube right? Wrong. It's gone with the "Drive" approach.
Google Photos? Another fan of the quick exit. ("Drive") (7/n)

In short. Default behaviour appears to be "You're at the top, quit". At least that's how it works without special coding; anything else requires specific code.
Essentially: it is ambiguous. It is ambiguous even in apps developed BY THE COMPANY WHO DESIGNED IT. (8/n)

Yes. I checked the material design guidelines. The page all about tabbed ui does not contain the word "back". (9/n)

If we had a big budget and more time, we could A/B test that. Because, I don't know if that original customer's complaint is essentially correct, or he's not used to Android. 🤷🏼 (10/n)

What I do know, is it seems kinda crazy that something like this which is around a long time can be described as "ambiguous".
Thanks for listening. And if you can point to something that claims "correct" behaviour, I'd love to read it.
(11/11)