People in the field of Human Computer Interaction have known for a long time that pocket-sized, wireless computers were coming. The question has been what’s the best way to interact with such a device. Apple’s design focuses on viewing and touching, but not the tactile keyboard. The success of the iPhone may hinge on that decision, according to the Seattle Times on Monday.

The iPod introduced the era of the minimalist interface, replacing option buttons with scrolling and finger sliding. Now, Human Computer Interface (HCI) experts, while happy to see some of their popular ideas for a touch screen commercialized, are still wondering if Apple chose the best way to interact with a pocket computer, mobile phone and iPod combo.

"The question is, will people mind not having usable buttons?" James Landay, an HCI expert at the University of Washington said. "I think that’s a big issue."

Another question is whether Apple’s design decision was 100 percent based on the best way to interact with such a device or whether it was influenced by Apple’s desire to sell content on the device. That’s a subtle shift from the primary usage of a mobile phone.

Scott Klemmer is a professor and co-director of the HCI Group at Stanford. He thinks the lack of a "tactile input device" will be the iPhone’s Achilles’ heel. "Design is fundamentally about choice and making tough decisions," Mr. Klemmer said. "What’s interesting to me with the iPhone is Apple has privileged the viewing experience over the text input experience."

That naturally makes the iPhone a killer platform for media, but makes it less useful for people who are accustomed to text messaging.

Apple iPhone Welcome Video

iPO notes that, to answer that objection, Apple recentlly published an iPhone welcome video showing how to type with two thumbs (15m01s into the video), BlackBerry style. "In about a week, you’ll be typing faster on an iPhone than any other small keyboard," Apple said.

Finally, Apple has the unique ability to show us new ways of thinking and nourish the popularity. In sense, asking if the lack of a tactile keyboard is a weakness of the iPhone may be like the days when we asked if the lack of a 3.5-inch floppy disk was a killer weakness of the original iMac.