A while back on my old blog, I wrote about the role of fixed navigation buttons on smartphones. Looking back to that time, the convention was:

• Android: most commonly four buttons on phone, no button on tablet (though there were variations)
• iOS: one button, still unchanged despite rumors to the contrary
• Windows Phone three buttons, also unchanged
• webOS: one button, made somewhat redundant by swipe gestures on the Touchpad
• Playbook OS: no buttons, which held up for the BlackBerry 10 OS.

MeeGo, in its cameo moment upon the smartphone stage, had no fixed navigation buttons. And from what I can see of Sailfish or Firefox OS, it is also true for them in their initial implementations. More significantly (at least for the U.S. market), Windows 8 and RT tablets have one Start (home) button, which means that, unlike with Android, the user interfaces are subject to de jure discontinuity Over time, the Search button has waned on Android phones, and most recent flagships support either three (Droid DNA) or no buttons. The trend seems to be toward the latter with the Sony XPERIA Z Ultra, Moto X and LG G2.

Samsung, though, has taken an interesting hybrid approach on its most recent handsets such as the Galaxy Note II and Galaxy S4, centering a physical “Home” button between two capacitive ones (that I still count that as three overall). More curiously, though, and starting with the Galaxy Note 8.0, Samsung ha shifted from no buttons on its tablets to the same kind of button layout on its tablets. Indeed, the Galaxy Note 8.0 looks very much like a large Galaxy S4.

Including the button on a smaller tablet makes sense as it enables more screen real estate to be used by apps. This may be especially true for an S-Pen-enabled device where there’s some presumption of use in portrait landscape a la notepad. And this is particularly true for Samsung, which of course wants to reinforce industrial design and user interface across phone and tablet as Apple has done. Still, three buttons seems like too much on a tablet, and the placement gets increasingly awkward with larger sizes such as the latest Galaxy Tab 10.1. I think Samsung would do well to revert back to the buttonless design on at least that tablet, even if it takes a differentiation hit.