So what gives? For consumer experiences, HCI research should focus more on preparing—and industry on creating— new sweet-spot devices, rather than wasting time on baroque extensions of existing paradigms. To make history, look for that sweet spot providing the broad public with a device/ application/service to which they had no usable, affordable access before.

This, by the way, is also why HCI is key to innovative products. Sweet-spot solutions are task-centered in an unprecedented way; they are uncluttered, simple, and elegant.

The other day, after Googling another nearby store on my iPhone, because the one where we were didn’t have what we wanted, my sweetheart said, “You know, it’s really incredible how useful this iPhone is.” Now excuse me while I go and drool some more.

March + April 2008

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ABOUT THE AUTHOR Jan Borchers is a professor of computer science at RWTH Aachen University in Germany, where he heads the Media Computing Group, studying interaction with audio and video streams, mobile devices, and ubicomp environments. He has currently deserted his students for a sabbatical at UC San Diego to write random rants like this. He’s not getting paid for this article by Tom Tom, Apple, or Psion, although he will happily provide them with his banking details should they feel obliged to change that. He can be found at http://hci.rwth-aachen.de.

squarely into their baroque stage. In a 2007 study we did for Germany’s largest mobile-technology consumer magazine, connect, virtually all models we tested gave users problems with even the most basic and essential tasks: turn on, mute ringer, call number. Being able to browse the Web, take pictures, watch or record movies wherever you are is great, mind you, but it has overloaded the sweet-spot product and interaction design of the traditional mobile phone beyond recovery.

The only way out was to radically rethink the product. Apple’s iPhone did that to a degree, removing the keyboard and its dead-end soft-key concept and introducing multitouch to more directly interact with what’s on screen. It was far from perfect, but mobile browsing became good enough to become useful, giving you the tingling feeling of a new sweet-spot candidate.

Or take home internet access. After listening to our chirping modems for years, it was DSL’s unlimited-time, unlimited-vol-ume flat rate that changed how we thought about the Internet: Suddenly it was free to access the Net after paying a fixed monthly fee. Getting movie showtimes, driving instructions, or just a recipe for cranberry sauce became a snap. And flat rates made our systems always-on, with no dial-in delays. Since then providers have tried to integrate DSL, landline, cable, and cell phone contracts, leading to a maze of options with some further savings but no impact anywhere near that of the flat-rate DSL effect.

Occasionally, consumers will

go as far as backpedaling to find the sweet spot again. My last microwaves were all of the one-dial-for-time, one-dial-for-power, go-bing-at-the-end variety, and I can’t be alone, judging from what’s in stores. On my Sony-Ericsson T630 phone, I quickly replaced the default, distracting, low-contrast ColorBombs theme with a simple black and white one that let me focus on the important stuff.

The desktop metaphor had its sweet spot with the release of the Xerox Star and Apple Macintosh between 1981 and 1984. Since then its basic idea has remained unchanged, as is often lamented, and only small improvements and secondary features have made it onto our screens. Smaller sweet spots were reached within that metaphor (full-text search or Apple’s Time Machine backup come to mind), but most new, more colorful and feature-rich systems fall into the baroque phase. Sometimes I fantasize about a system that returns the desktop metaphor to its sweet spot (not that that would be very useful today), or that finds the right revolutionary approach to kick the desktop metaphor out the door.

Other examples include the original iPod, or the affordable consumer digital camera with enough resolution for standardsize prints, letting you take, immediately check, and delete shots for free. TiVos changed TV viewing habits fundamentally, and personally, I would include iChat AV, for letting me show our new kitchen to my mom some years ago, walking around with a laptop and iSight camera (okay, still geeky).