Multitouch: How Many Touch Points Do You Need?
You’re seeing a lot of them at tradeshows these days. They’re even showing up in some hotel lobbies and elsewhere. They’re large-format multitouch displays and videowalls. Recently I sat down with John Dixon, a product manager here at Planar Systems, for some insight into the trends surrounding large touchscreen displays.
Me: We’re seeing more adoption of multitouch technology on videowalls. Where are you seeing growth and what’s driving adoption?
John: Retailers, museums, universities, and businesses are all rapidly adopting multitouch technology right now. Some customers are using multitouch technology as digital signage to engage and interact with their customers, and to further build their brand messaging. Others are using it to collaborate in conference and briefing rooms.
Me: Like any new technology, the industry seems to fixate on certain specifications. For touch, it’s the number of touches. I only have 10 fingers. Why would I need a touch wall with 32 or more simultaneous touch points?
John: With both Windows and Macintosh operating systems, multitouch displays can recognize gestures and touch points and perform certain functions. As you say, there is no gesture that requires 32 simultaneous touch points, but as the surface area of the display grows, the display changes from a single user interface into one that’s used by multiple people. What’s more, those people might not be using their whole hand, and not just a single finger. The system could then register each person as five touch points or more. The need for touches can add up quickly.
Me: When do you advise customers to use gesture technology, such as that used in the Microsoft Kinect system, versus touch?
John: Gesture holds a lot of promise, but the performance and accuracy are not there to provide fine-level control of content. As a camera-based system, there is no uniform set of actions that people know to take. To select something, do users push with their hand, point with their finger, or grab it in mid-air with their fist? For it to be a natural user experience, it is best not to require specialized training or to mimic the interfaces of other well-known devices. This is why multitouch is so powerful. It works similarly to how people interact with their phones and tablets. It works how you expect it to work.
Me: So, how can I test for myself the quality of a multitouch system? How can I tell a good one from a poor one?
John: We’ve developed a series of tests to identify high-performing systems and help users avoid ones that don’t perform as well. Here are a few tips:
First, use your fist instead of a single finger. Does the display recognize it as a single touch?
Second, touch the screen and observe the accuracy of the touch. Is it aligned perfectly with your touch point?
Third, using a drawing program, draw with two fingers simultaneously. Then rotate your wrist, leaving the two fingers on the touch surface. Great touch systems won’t get confused as to which finger was which and will continue to draw the lines overlapping.
Fourth, if you have a canvas with two images on it, take those two images, one in each hand, and maneuver them as close together as you can. Did the display confuse the images or your fingers? That effect will cause problems with fine detail content.
Finally, place your complete arm on the display and touch another point on the display with your opposite hand. Does the display detect the touch point of the other hand?
Try these during your next touchscreen encounter and you’ll clearly see where some technologies don’t keep pace with user expectations.
Me: For public venue installations, a videowall enabled with touch can take some serious abuse. How do you protect your investment while allowing for this level of interactivity?
John: That can be a challenge. It’s important to protect and strengthen the videowall without trapping heat unnecessarily, which causes displays to fail for other reasons, and without diminishing the contrast and readability of the displays, which can often occur when displays are put behind cover glass. You want solutions that are modular, create less parallax error, and add durability for public venue installations, while also providing a smooth surface across the glass, which improves the overall touch experience. A multitouch videowall is first and foremost a videowall and it must look great, attract people to it, and perform well over time.
Me: Thanks, John. Now, a question for readers:
Where are you seeing multitouch deployments and what do you think the future holds for large-scale touch installations?