For tablets, does size matter?

Are 10 inches better than 7? Or are they just too much to handle? Conversely, are 7 inches too few to do the job well? The debate rages on as the world prepares for an onslaught of Android tablets and the RIM PlayBook tablet this spring, a year after the iPad shipped and created a whole new category of computing. The PlayBook and nearly all the announced Android tablets have 7-inch screens, whereas the iPad has a 10-inch screen.

Apple CEO Steve Jobs has decried the 7-inch size as too small, and his product instincts are unrivaled. So why the rush to 7-inch screens by everyone else seeking to capture some of the iPad magic? The question came up this week when I met with several executives from Research in Motion, who showed me a prototype of the forthcoming 7-inch PlayBook. I asked why RIM chose the 7-inch form factor, and the execs asked me what I preferred as I use both a (10-inch) iPad and a (7-inch) Samsung Galaxy Tab.

Where bigger is better The 10-inch size has several advantages, and I have no doubt why Apple insists on that size for its iPad: The large expanse makes for a true desktop when watching videos. Given Apple’s iTunes play, which includes video sales and rentals, a home-entertainment-style screen makes sense.

The 10-inch size also makes Web surfing feel normal, similar to the desktop experience. Many websites are complex, and you really benefit from a large screen to be able to read their screens and navigate their content. Ditto for productivity-oriented applications, such as presentation software, spreadsheet editors, and email clients. And for typing-oriented applications, the iPad’s on-screen keyboard is full-size when in landscape mode, so you can touch-type as if you were using a PC or laptop. For people who view the tablet as a lightweight laptop replacement, the 10-inch screen also makes sense (it’s the same as a typical netbook).

Where smaller is better The 7-inch size has several advantages as well. It’s easy to hold a 7-inch tablet in one hand and do stuff with your other hand. By contrast, to use an iPad for more than a few minutes, you really need to be stationary, preferably with the Pad resting on a surface. Otherwise, it’s awkward to hold with one hand while tapping with the other.

The smaller 7-inch form factor makes a lot of sense for activities done while you’re in motion. Touring an art gallery, entering tolerance values on a factory floor, inspecting construction work at a job site, recording drug dispension at the patient bedside, and completing surveys in a waiting room are all examples of where the smaller size makes sense. Notice that most of those are “field force” uses, so RIM’s decision to make its PlayBook a 7-inch device makes sense given its historic corporate market. For consumer users — the target of the Android device makers — the 7-inch size makes sense for game-playing, casual email, and casual personal video-playing (such as YouTube snippets).

Where size doesn’t matter (much) There are many activities for which either a 10- or 7-inch tablet are quite suitable. Playing Angry Birds and most games is equally pleasant on the two form factors. If you have a single email box and don’t use folders extensively to manage those emails, both sizes are perfectly acceptable. Calendar apps, e-book readers, and playback apps (such as to watch a presentation or training video) also work well in both sizes.

It’s true that the larger screen size often feels richer in such cases, but that’s the same dynamic as when you watch a movie on someone’s 46-inch TV and come home to your 42-inch. You marvel at your friend’s 46-inch screen while watching it, but are perfectly happy back at home with your 42-inch model. We may prefer bigger, but other practical factors — cost, bulkiness, and so on — usually outweigh that preference.

Some people claim the iPad is too big to easily carry. That’s nonsense. It weighs 1.5 pounds and is easily held in one hand, folded against the arm as you walk. It’s the same size as a typical notepad and about the same weight as those leather-bound portfolios and calendars that many people carry. It slips easily into a backback or case — or airline seatback compartment. (I often panic because — since it’s so much lighter than my laptop — I think I left it behind, when in fact it’s securely hiding in my backpack.) Because the 7-inch tablets don’t fit in most pockets, I’ve found that I end up carrying them the same way as I do the iPad, so for carrying-around purposes, they’re equivalent.

If you plan to use a tablet as a lightweight laptop, you really will want a (10-inch) iPad or one of the few 10-inch Android tablets announced so far, such as the Motorola Xoom. If your intended use is in a job where you work primarily on your feet, can’t count on having a place to rest the tablet for data entry, and move around a lot (field force work), a 7-inch tablet makes more sense. For home entertainment, my guess is you’ll end up with both sizes.

Apple can probably get away with having just a 10-inch model, given its “big media” and “new PC” aims. Plus, it has the 3.5-inch iPod Touch to fill the portable niche, and that device makes for a great portable game-player, e-book reader, and basic email and calendar device. However, it might be surprised by how popular a 7-inch model could be in several market segments.

RIM, Hewlett-Packard (which is making noises about “radically different” WebOS tablets), and the Android device makers should offer both sizes — especially RIM and HP. Why? Because these companies are trying to play to the broad business and consumer markets, both of which have segments that each of the two sizes better serves. There’s no reason their customers should compromise when the device makers could accommodate both sizes through separate models.

The real trick to that strategy, of course, is not in the hardware. The underlying OSes and the applications that run on it need to autoadjust based on the size. Apple has shown how that should work in its iOS, where apps can be designed for both iPhones and iPads, adjusting their display and even functionality to the specific device. RIM has shown some understanding of that strategy in its PlayBook, in how the RIM messaging and calendar apps appear in a richer view on the PlayBook than on a BlackBerry smartphone, but it’s unclear if RIM has extended that autoadaption capabillity to its third-party software developers. As for Google, even less is really known about its tablet-oriented Android 3.0 Honeycomb OS, so customers and developers alike will have to wait and see.

In the meantime, we can stop playing screen-size envy games and instead look for the size that fits our needs best.

This article, “For tablets, does size matter?,” was originally published at InfoWorld.com. Read more of Galen Gruman’s Mobile Edge blog and follow the latest developments in mobile technology at InfoWorld.com. Follow Galen’s mobile musings on Twitter at MobileGalen. For the latest developments in business technology news, follow InfoWorld.com on Twitter.