news
Technology | DOI: 10.1145/2380656.2380663
Gary Anthes
Zoom in, Zoom out
Drilling down to more detail on a computer screen,
or moving out to see the context, is basic. But it’s hardly simple
and, after 20 years, innovations are still occurring.

ZooMing, the aBiLitY to move in and out of information to show different levels of de- tail on a computer display, would seem the most mundane of capabilities. Indeed, zooming in various guises has been possible for at least two decades, and it’s the rare application today that does not give users at least a rudimentary zooming ability.

But the story of zoom technology is surprisingly complex. There are many ways to produce a zoom effect, and many of the ideas tried over the years have seemed to hold enormous promise, but have languished, often because the cost to the user exceeds the benefit that the user perceives.

Today innovation lies less in the development of new zoom technologies and more in the application of existing ones. One such application, called ChronoZoom, can seamlessly zoom into a gigantic multimedia database at levels from millenniums to nanoseconds. This kind of deep zooming is an example of what has become known as the “zoomable user interface,” or ZUI.

It seems an impossibly ambitious goal: “visualizing the history of everything.” ChronoZoom, however, may plausibly enable just that. ChronoZoom is essentially an online interactive timeline using a nonlinear, or variable scale, presentation. At the top of your screen lies a horizontal timeline stretching at the left from the Big Bang 13. 7 billion years ago to today on the far right. In between, you might zoom in on a point at 12 billion years ago and watch a video about how dying stars began to create new elements. Or you might zoom in to the year 1300 to learn about the birth of the Ottoman Empire, or to Jan. 24, 2012 to learn about the birth of Princess Athena Marguerite Françoise Marie of Denmark. At any point on this “virtual canvas” you could be presented with relevant photographs, graphs, video, audio,

a Web-based timeline, chronoZoom enables users to see the scale of time over cosmic, geologic, biological, and social periods.

 

or text. “It could scale down to one nanosecond if we had content for a nanosecond,” says Rane Johnson-Stempson, a director at Microsoft Research.

ChronoZoom is an open source system led by the Outercurve Foundation and being built by scientists at the University of California, Berkeley, Microsoft Research, Moscow State University, the University of Washington, and nearly 20 subject matter experts from around the world. ChronoZoom runs on Microsoft’s Azure cloud service and uses SQL Azure for storage. It has HTML5 on the front end and some 100 APIs to integrate existing content and software on the back end. ChronoZoom also operates on a variety of platforms, including mobile devices such as iPads, iPhones, Android devices, and Windows Phone.

The problem ChronoZoom and other ZUIs attempt to solve could not be simpler. “There is more information than fits on the screen,” says Ben Bederson, a computer science professor at the University of Maryland and a pioneer in ZUI technology. This problem can be overcome by scrolling, linking, searching, and zooming into successively dense representations of the information. All file and Web browsers and image and document editors offer one or more of these capabilities.

But, according to Bederson, the term ZUI has come to refer specifically to those systems—such as Google Maps— that provide both spatially and temporally changing views to navigate at different scales, among multiple objects such as text documents, photographs, or entire ensembles such as presentations.

People are attracted to ZUIs for at least three reasons, Bederson says. They are engaging, naturally suited to human visual perception abilities; they are visually rich, offering multiple degrees of freedom; and they are potentially simple, offering the ability to find something in a place, much as you might locate a document on your physical desktop.

the march of Zuis

Ken Perlin and David Fox, computer scientists at New York University, kicked off the ZUI era in 1993 with a paper titled “Pad—An Alternative Approach to the Computer Interface.” Pad was “an infinite, two-dimensional information plane that is shared among users,” they noted. “Every object occupies a well-defined region on the Pad surface.” Users peered into virtual magnifying glasses called portals, which could be moved to any part of the surface the user wanted to look into. Each mouse click instantly produced a view twice or half the size of