Getting the user interface right

I’ve talked about user interfaces in these pages a few times before. The thing is, I’m not a user-interface expert. But, as with wine and art, I know what I like.

And, while not being an expert, I’ve often been called upon to design a user interface nonetheless, or, at least, an part of one. It’s what sometimes happens with programmers. I always hope that my UIs will be reasonable — I like them fine, and, as I said, I know what I like. But will they suit the general public? Qui sait?

My first general rule, and what I prefer when I’m using other people’s interfaces, is to make sure that the things one would most commonly need to do are quickly and easily accessible, and obvious. The same goes for the important things, which might be less common but which you have to get to quickly when you do need them. Second priority goes to a set of likely actions that will be used less often. Everything else can be hidden behind an Advanced button, selection, or tab.

This stuff’s especially important on mobile devices, which have smaller screens and more limited means of interaction.

What are the most common and most important things you’ll need to do right after you place a phone call? I think they’re these:

1. Hang up. You called the wrong person, or hadn’t intended to place a call at all.
2. Select between the handset and the speakerphone modes.
3. Switch to another program or view while continuing the call. Maybe you need to refer to an email message, or a calendar or address-book entry, as soon as the person answers.

I had occasion to place a call on someone else’s phone recently, and I realized that it was set up perfectly for this. The phone has two buttons, on the left and right, and the screen displays the functions that these buttons will perform. There’s a button that always activates the phone’s menu, and there’s another that always hangs up a call. One of the variable-function buttons is, while you’re on a call, labelled Speaker or Handset, and will toggle between them. Switching to speakerphone mode, which is what I needed to do, required a single button-press, and was instantaneous.

That’s one thing that bothers me about the BlackBerry’s UI when I’m making a call. To toggle speakerphone mode, I have to press the menu button, find Activate Speakerphone on the menu, roll down to it, and click it. That’s not terrible — I know where it is, and it’s easy enough to do it. But it takes several seconds, during which time I can’t hear the phone. A function such as that, which is one of the top three most likely things you’d need to do, should be even easier. It should be a single button, or a tap on a touch-screen.

What’s more, the BlackBerry menu is busy and cluttered. Here’s what the menu looks like when I’m on a call:

Help

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End Call
Hold
Enhance Call Audio
Mute
Notes

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New Call
Call Voice Mail

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Activate Speakerphone

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View Address Book
View Calendar
View Messages

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Switch Application
Home Screen

Those are all things I’m likely to want to do, so that’s good. But several of them can be done in other ways (there are at least two ways to end the call, three ways to switch to the home screen, and two ways to switch applications; also, I can view my address book, calendar, and messages by going to the home screen and selecting them there). I’d prefer having Speakerphone and Mute as functions directly on the phone screen. But, oddly, there’s nothing on that screen to interact with, once you place a call.

The BlackBerry folks get so many things right. But they miss on some basics.