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