Thursday, March 29, 2007

GPS for Dogs

Just when you thought you've seen it all, Garmin is selling a GPS for dogs. No, not to help the dogs navigate (that would be scary), but to help owners find their dogs.

Sunday, March 25, 2007

WorldSpotting, A New Class of Ubicomp Apps

There's an interesting class of ubicomp apps that I'm calling WorldSpotting. These kinds of apps are mobile systems where people act both as sensors and as users of the system. Some examples WorldSpotting applications include:
  • Gawker Stalker, which lets you track and send updates on where celebrities are in Manhattan
  • Mobile Media Metadata, which lets you easily tag photos with place names, based on what other people have labeled
  • Wardriving, where people both collect data on the location of WiFi access points and use those, for general network access or for location positioning
  • Bustle, a system we are developing that lets you contribute information on how busy a place is, as well as query how busy places are. An example application would be to see how busy the local cafe is.
The pros of WorldSpotting applications is that you can get massive scale without having to install lots of infrastructure, as has typically been done for many ubiquitous computing applications. Thus, WorldSpotting is a hybrid between personal ubiquitous computing, that is applications that serve and describe individuals, and place-based ubiquitous computing, applications that serve and describe places.

However, there are many challenges in building WorldSpotting applications, many of which we found through a great deal of trial and error in building and evaluating Bustle. These include:
  • How to actually do sensing? Sensing can be done manually, as in Gawker Stalker, or automatically. Here, the issues include timeliness, accuracy, overhead for users, and the cost of additional sensors (which may be the greatest barrier, since manufacturers tend to be conservative due to costs). With Bustle, we overcame this problem by using WiFi, which is now a commodity on laptops.
  • How to share sensed information? Since we don't have ubiquitous wireless networking yet, it is possible to collect data and then share it later on once re-connected to the network. In some cases, this is still useful, for example WarDriving, but in other cases, stale data is useless.
  • How to detect and prevent cheating? This is a question we often get about Bustle, which is, what is to prevent cafe owners from saying that there place is only moderately busy, to fool people into going there? There isn't a clear solution yet, but one possibility is reputation management, looking for people whose data consistently matches other people's. Another is to look for anomalies, for example, a computer that only reports from one location.
  • How to calibrate world models? One of the issues we had with Bustle is that we could automatically sense the number of WiFi devices, but needed some human interaction to translate that into the number of people and the number of open tables in an area. With enough people, you could do statistical techniques to calibrate what sensed readings actually mean in practice.
  • How to manage end-user privacy? One of the potential risks in WorldSpotting is that people who contribute data can be tracked. Another potential risk is sensor data mining, looking for people whose readings are consistently similar, which can be used to infer that there is some kind of relationship. In Bustle, we tried to minimize this by using anonymous readings and by eliminating as much data as possible on the client-side, before the data is shipped to us. For example, we don't get any data about WiFi MAC addresses, nor do we want any.
  • How to provide incentives to collecting data? This is another question we often get about Bustle, which is why a person would want to collect and share data. From a game theory perspective, there is little upside to sharing data, but a fair amount of possible downside, in terms of privacy and overhead. One possible solution here is to make everything automatic, so that people don't have to do anything special at all. Another possible solution is to provide a scoreboard. One need only look at the SETI@Home statistics to see that there will be some set of people who will fight and fight hard to be on top. It's also interesting to point out that a non-trivial number of people contribute wardriving data, with little to personally gain. However, these issues point to a larger and deeper question, namely...
  • How many people does one need for coverage? This is still an open question, but our early data for Bustle suggested that we only needed about 20 participants to cover half of the buildings on the CMU campus. Obviously, more is better, but my instinct here says that you would need fewer people than you might think to get good enough data in practice.
To wrap up, I though I'd include other possibly interesting WorldSpotting applications:
  • Cars that have "bump" sensors in them, to detect potholes in the ground. With enough cars, you could have a real-time map of what roads in a city need to be fixed
  • Bus Finder. With enough people running the app on their phone, you could have real-time maps showing where the buses are and how busy they are. This is especially useful in Pittsburgh, since buses tend to be full on snowy and rainy days, and hence don't stop for new passengers.
  • Airport lines. You could have real-time data on how long the lines for tickets and for the security checks are. I've personally missed more than one flight by underestimating this.

Thursday, March 22, 2007

But Capybara Aren't Fish!

If you hang around me long enough, you'll eventually hear my story about how South Americans consider capybara's, the world's largest rodent, as fish. (If you hang around me long enough, you'll also find out that Regis Philbin is my mortal enemy and that I once found myself with a black guy and two Filipinos in the middle of a KKK march, but those are stories for another time).

To wit, one of my friends (James Lin, of Lincoln Highway fame) has just forwarded me an article from the New York Times about the world's most delicious rodent (I bet Amazon's statistically improbable phrases would have fun with that one). As you can see in the picture below, it's pretty obvious that capybara aren't fish.

So here's the Gray Lady on rodent-fish:

The annual hunt comes before Easter, when capybara has a status in Venezuela similar to that of turkey during Thanksgiving. While the Roman Catholic Church generally forbids eating meat during certain days of Lent, many Venezuelans insist that the capybara is more akin to fish than to meat.


That may have something to do with how salted capybara tastes, resembling a mixture of sardines and pork. Legend has it that eating capybara, known here as chig├╝ire (pronounced chee-GWEE-reh), got a boost in the 18th century when the local clergy asked the Vatican to give capybara the status of fish.

Perceptive Pixel - Large Interactive Touchscreens

Jefferson Han, the person whose work on interactive touchscreens has been all over YouTube and featured at the TED conference, has founded a startup to commercialize his technologies.

I think it's interesting that large interactive screens have been around for quite a while. For example, Stanford's iRoom, Fraunhofer IPSI's iLand, the old Liveworks (that commercialized the LiveBoard), Smart Technologies (that sells SmartBoards), and MERL's DiamondTouch, just to name a few.

I remember being the session chair for Jefferson when he presented at UIST 2005, and thinking that there were two key differences. The first is that the technology is cheaper than anything else out there. Ridiculously cheaper by an order of magnitude. Most large interactive displays cost thousands of dollars, whereas Jefferson's work only required a cheap sheet of plexiglass, a projector, and a camera. It's cheap enough that I've been trying to encourage students in my classes to build their own (without any results yet though).

But I don't think this was enough to capture the blogosphere's attention. I think what really took hold was the smooth interaction techniques that he's developed. Most of them aren't novel from an interaction standpoint, but they highly polished and look really fun to use. Take a look at the original videos of the multi-touch screen and the videos showing the larger screens used for the startup, and you'll see what I mean. They've got a fast response rate, a certain flair, and a fun sense of play, definitely things we should pay more attention to in research.

Thursday, March 15, 2007

Motion Computing C5 Mobile Clinical Assistant

Looks like this is another push for tablet PCs in hospitals. The platform itself seems quite nice, in that it has wireless networking, barcode readers and a built-in camera to make it easy to get data, and has smooth surfaces all around to make it easy to clean and disinfect.

How Many People Does it Take to Change the World?

One interesting thing that happened last month was that I got to meet Alan Kay, one of the researchers at PARC that helped invent our modern conception of personal computing back in the 1970s. He said many things that struck me, but one stood out in particular, namely that it only took about 25 researchers at PARC to develop it all, from ethernet to GUIs, from Smalltalk to the laser printer. The key to it all, though, was having a shared vision that 25 really smart and independent people could agree on.

This is something I've noticed about the original Ubiquitous Computing project as well (also done at PARC), in that there was a grand shared vision that a lot of really smart people believed in and pushed for.

However, I'm not sure if this is something we could easily re-create today. It's hard enough to get 25 people to agree on anything, but there's also the funding issue, in that NSF can't fund projects that large and DARPA no longer will. I also don't think that this is something that could have happened in academia, since we're all fighting to establish our own independent identities and reputations. I think things like the PC and Ubiquitous Computing could have only happened in industry, where you can have a strong enough management that can bash enough heads to make things happen.