This video does a good job of explaining how the iPhone virtual keyboard works and what typing performance you can expect from it. Nicely done.
For anyone that’s familiar with DialKeys on a UMPC, right away you’ll see that Apple has something different here. According to the video, the iPhone leverages a couple heuristics to improve the typing experience. For one, they use a dictionary–kind of like the Tablet PC’s handwriting recognizer uses a dictionary to improve its recognition accuracy. In this case, the iPhone attempts to adjust for mistargeted letters based on what letters make sense near where the user has made contact with the display. The keyboard also transparently adjusts key sizes based on what letters make sense at a given time. If only the letter “e” makes sense for the given letters already typed, for instance, then the “e” key hit target gets larger. The difference is not shown to the user, but it does help to improve recognition according to the Apple video.
One interesting thing about the video is how so much of what is said in terms of how the virtual keyboard works, could also be said–or somewhat described–about the way the Tablet PC’s keyboard works. Yep. There’s a very similar pattern here that both Apple and Microsoft have independently arrived at. Both take awhile to get used to. Both automatically adjust to the context. Both employ dictionaries to improve recognition.
One question I’ve had is whether handwriting recognition on the Tablet PC with all its automatic adjustments would be faster or slower than two handed typing on the iPhone’s virtual keyboard. I don’t have an iPhone to experiment with, so for now a demo within the video will have to do. Near the last fifth of the video, the speaker types the following two sentences using his thumbs:
I know a great place a couple blocks away. I will make a reservation for three.
I tried writing along with the typer to see if my handwriting could keep up. Unfortunately, the person was able to type slightly faster than I could write. This wouldn’t be a surprise on a full-screen keyboard, but it says a lot on a small, handheld device with a virtual keyboard. I consistently was about a 1/2 to a second behind.
You might want to try this experiment yourself. With your Tablet PC in hand, reset the video to where the user begins to demonstrate two thumb typing. Try writing along. See if you can finish first or about the same time.
After making several attempts myself, I began to realize that word choice in the sentences probably plays a little part here. For instance, if I replace “I will” with the contraction “I’ll”, this is easy to do when handwriting. However, I wonder if the contraction would slow down the typer. Similarly, I noticed that the typer isn’t really holding the device. It appears to be on a stand. I definitely can see why holding the device still is a very good idea here, however, I wonder how effective fast typing is when showing it in progress to someone else. I’ve learned over the years, that showing someone how the Tablet works while handwriting and having the display rotated so that both myself and the other person can see what I’m doing, can lead to less than ideal demos. For one, targeting isn’t quite right. In addition, you often can’t quite see what you’re doing. Anyway, I was wondering if typing performance would change if the iPhone was being held in the person’s hand. I can’t wait to find out. So far, the virtual keyboard looks promising.