INTRODUCTION:
METAMORPHOSIS
by Chris Harrison, Editor-in-Chief
Big changes are coming to Crossroads Over the next few months, you’ll begin to see sweeping changes to ACM’s student magazine. Jumpstarting this effort is a brand new editorial team from all over the globe. I am very excited
to be starting as ACM Crossroads new editor-in-chief. Some background on myself: I’m a third year
PhD student at Carnegie Mellon University working on novel input and interaction techniques. You
can read about many of my research projects at www.chrisharrison.net.
I’m also honored to introduce an amazing lineup of senior staff. We
are privileged to be working with a professional advisor at ACM head-
quarters, Jill Duffy, who was with Game Developer magazine for many
years before coming to ACM full-time as a senior editor.
Tom Bartindale, a human-computer interaction PhD student at
Newcastle University, is our new departments editor. Tom will be
spearheading the development of several new and exciting sections in
Crossroads, content that will enhance the exciting feature articles tied
to hot topics—more on that in future issues.
A veteran to the magazine, Justin Solomon, soon to finish his
degree in computer science at Stanford University, will continue in his
current and indispensible role as managing editor. Ryan K. L. Ko of
Nanyang Technical University in Singapore, who has also been on the
Crossroads’ masthead in the past, has been promoted to deputy editor.
I’m also pleased to recognize Malay Bhattacharyya of Indian
Statistical Institute, who has been named an assistant editor, and to
welcome another assistant editor, James Stanier of the University of
Sussex, alongside all the other contributing editors who help with con-
tent development and assist authors in readying text for publication.
The Social Web
In coming issues of Crossroads, the publication will increasingly focus
on specific topic areas, ones of interest, importance, and with open
problems in a variety of technical fields. This issue is dedicated to the
social Web, an unknown entity a decade ago that now pervades our lives.
Facebook has in excess of 300 million users, making it the fourth
largest “nation” on the planet by population. Social Web sites are also
among the most trafficked destinations on the World Wide Web,
responsible for millions of photos, posts, tweets, winks and pokes
every day. Communities on Digg, StumbleUpon, Yahoo! Answers,
Twitter, Wikipedia, Mechanical Turk, LinkedIn, and scores more are
just as vibrant and constitute millions of hours of work and play.
Many view this democratization and communication transforma-
tion as one of the key components of the Web 2.0 movement. In this
issue, you’ll find several feature articles that look at different aspects
of the social Web movement and technologies.
The next issue of Crossroads, due out in Spring 2010, will investi-
gate different aspects of cloud computing. In the meantime, please
sent letters to the editor with feedback and ideas about Crossroads to
crossroads@acm.org.
Biography
Editor-in-chief Chris Harrison is a PhD student in the Human-
Computer Interaction Institute at Carnegie Mellon University. His re-
search interests primarily focus on novel input methods and interaction
technologies, especially those that leverage hardware and the environment
in new and compelling ways. Over the past four years, he has worked on
several projects in the area of social computing and input methods at IBM
Research, AT&T Labs, and most recently, Microsoft Research.
About the Cover
The image on the cover of the magazine is a section of a visualization of a
Twitter StreamGraph created by Jeff Clark at Neoformix. Twitter Stream
Graphs allow a person to enter a query of interest, retrieve the latest 1,000
tweets (or messages sent on Twitter) matching the query using the Twitter
Search API, analyze the text in those tweets to find the most common non-
trivial words, and output a StreamGraph visualization of the results.
The cover image was generated using the term “data visualization” as
the query.
“I find this type of graphic appealing, ” says Clark, “because it gives
visual prominence to the larger series. It has weaknesses as well. It’s
harder to tell which series is larger at a given location than it would be
with a simple line chart. ”
The application was created in a Java-based processing development
environment. The Porter Stemming algorithm was used to count all the
various forms of a word together, but the most common form used in the
data is shown as the label.
Clark says he has also experimented with creating StreamGraphs for
narrative or continuous text, such a speech given by U.S. President Barack
Obama at Kettering University in Flint, Michigan. “The graph does a rea-
sonable job of illustrating the primary themes of the speech, which words
were used together, and at what point during the delivery, ” Clark says.
