I just posted a Testing the Limits interview with Jakob Nielsen – aka the King of Usability – over on the uTest Blog. The subject matter will of great interest to readers of this blog, as we had an in-depth discussion on the past, present and future of mobile applications. Here are a few clips where he discusses native apps vs. the mobile web, tablet usability issues and his take on the iPhone vs. Android situation.

On native apps vs. the mobile web:

JN: Apps are superior for 3 reasons:

• Empirically, users perform better with apps than with mobile sites in user testing.
• Apps are much better at supporting disconnected use and poor connectivity, both of which will continue to be important use cases for years to come. When I’m in London and don’t feel like being robbed by “roaming” fees, any native mapping app will beat Google Maps at getting me to the British Museum.
• Apps can be optimized for the specific hardware on each device. This will become more important in the future, as we get a broader range of devices.

Apps have the obvious downside of requiring more development resources, especially to be truly optimized for each device. If a company doesn’t have enough resources to do this right, it’s better to have a nice mobile site than a lame app.

A second downside of apps is that users have to install them. Our testing shows poor findability and usability in Apple’s Application Store, and many users won’t even bother downloading something at all for intermittent use. So ask yourself whether you’re really offering something within the hardcore mobile center of need: time-sensitive and/or location dependent, and whether your offer is truly compelling in this crowded space. Most companies are never going to make it big in mobile. In some cases all they need is to make their main website somewhat mobile-friendly. Many others should deliver a dedicated mobile site but not bother with apps.

On usability problems with tablets:

JN: The biggest problem in our recent tablet studies has been TMN: too much navigation. Also, too many inconsistently scrolling fields. Some tablet apps cram in so many weird features that users get overwhelmed and flail around without gaining mastery of the content.

I think that most designers of phone-based apps have recognized the need to limit the number of features and the number of wildly scrolling areas. The small screen imposes useful discipline that keeps out the worst excesses that still dilute usability on larger tablets.

While tablet UIs need to quiet down and become more consistent, that doesn’t mean that they should be phone designs with prettier graphics. The bigger screen allows for more features, and more focus on immersive use over longer periods of time than the quick hits that are most useful on phone-sized devices.

On iPhone vs. Android

JN: It’s a replay of the old tension between closed and open systems. Closed can be more tightly integrated and tends to have better usability because the entire system is architected as a whole. Open tends to be more unruly and confusing, but also offers a wider selection of choices. You could say Mac vs. Windows, or iOS vs. Android. Same basic issues. Windows won the former of these contests, and Android seems to be gaining ground in mobile.

The history lesson says that Windows eventually did emphasize usability and a stricter set of design guidelines starting around the time of Windows 95. But it’s taken them more than 15 years to overcome the legacy of bad usability in early Windows. You can’t just retrofit a strong user experience on top of a confused architecture. The peanut butter theory of design is false. (It claims that if you smear a thick enough layer on top, you can hide the taste of what’s below.)

In our current user testing, Android scores fairly well, but not as good as iPhone. For example, Android phones have several dedicated hard buttons (such as a menu button) that could theoretically help users do better than the iPhone with its single, overloaded button. Sadly, Android’s buttons are used inconsistently across devices and apps. As a result, users never know what each button will do, and thus never learn to use them or depend on them. Much stricter enforcement of design guidelines will be needed for Android to realize a usability advantage from its buttons.

That was one of the lessons from Macintosh software in the 1980s: developers who complied with the guidelines got better reviews and more customers, whereas inconsistent software got dinged by the Mac magazines. Because most early Mac software worked about the same, users could transfer their skills from one application to the next, and Mac owners bought about twice as many applications as PC owners.

Go read Part I of the interview in its entirety. Part II will be posted tomorrow.