Beware the Two-Tap Rule
Dr. John Morkes

I’m a fan of Yahoo for news and email, but I’m not a fan of their new “two-tap rule.” The rule states that once a user is in a Yahoo application, it should take only two taps to do anything the user wants to do. Fast-to-use apps are the goal here.

The two-tap rule sounds a lot like our field’s misguided “three-click rule,” which Expero cautioned against in 2007.

Rules like these, though well-intentioned, miss the mark. They equate user efficiency with one specific type of interaction (a tap or click), and they limit a designer’s ability to employ that interaction, even when it would be the best choice for the users. It’s unclear why that interaction is singled out when many other interactions also are part of the user experience. On a smartphone, if we say that only two taps are allowed, then wouldn’t we also need rules about the acceptable number of double taps (uh-oh—that’s two taps right there), drags, pinches, spreads, flicks, swipes, rotations, etc.?

Of course, minimizing the number of actions a user needs to take is a good idea. However, whether an app is efficient to use doesn’t depend on a specific number of taps or clicks—efficiency should be determined by users. During user experience testing, users often tell us that apps are faster to use when they require many taps or clicks as opposed to more scrolling (for example, when searching and filtering a large set of content or data).

A better rule to follow: “Our target users must consider our application efficient to use.” Similar rules (and testing) would help ensure that users consider the application usefuleasy to learn, and appealing before it’s released.

Screenshot A: This prototype application from Expero requires multiple taps as well as gestures with both hands—and users like it that way.

For complex apps and sites, where Expero specializes, rules that limit the number of taps, etc., simply would not work. This is especially true when user workflows are exploratory rather than linear. One of our applications runs on a 4K multitouch display on which the user interacts with huge data sets and visualizations by using both hands and a variety of gesture chords. In one scenario (see Screenshot A), the user does a two-finger spread on a map to reveal a loop between the fingers, while nearby a larger loop shows a camera view with virtual annotations in the scene. The user taps on a virtual sensor (shown in red) in the larger loop to reveal the sensor’s data, then taps perhaps several times to adjust its settings. There are lots of taps and other gestures in this scenario, but users consider it easy and fast.

Screenshot B: The Yahoo Weather app requires several taps to add a location, but that’s OK.

Yahoo’s current applications likely need to be redesigned if they are to follow their new two-tap rule. With Yahoo Weather (see Screenshot B) on my iPhone, for example, I had to tap 8 times to add a location:

Was it fast? Yes.

Do I care that it took me 8 taps instead of only 2? Not at all.