Pronounced “wisdom,” the WSDM (Web Search and Data Mining) Conference is one of many presented by ACM (Association for Computing Machinery), and “publishes original, high-quality papers related to search and data mining on the Web and the Social Web, with an emphasis on practical yet principled novel models of search and data mining, algorithm design and analysis, economic implications, and in-depth experimental analysis of accuracy and performance,” according to their site.
The paper’s motivation stems from a years-old debate in the fields of communication, marketing and sociology: do ordinary folk have the power to spread ideas in media? When Malcolm Gladwell’s “The Tipping Point,” released in 2000, asserted that a very specific portion of regular people were the most effective at spreading and magnifying ideas and products, Professor Watts took up academic arms.
“I had been arguing against this idea for some time,” said Watts. “Not that some people are not more influential than others, but just that there was any sort of magical effect, that you could sort of find some ordinary person and they would somehow trigger this massive cascade that would that would change the world. Which is really sort of the the promise of this book, and why everybody loved it so much. “
Professor Watts and team approached the debate with a foundational scientific perspective: if certain people are more influential, then computer science should be able to predict it.
“If it’s true that certain types of people, for whatever reason, happened to be disproportionately influential in the world and disproportionately good at getting other people to listen to them and to change their minds about some issue, you can do pretty well predicting how many retweets someone’s going to get just by looking at how many followers they have,” said Watts.
Right before the paper was published, Professor Watts recalls that mega influencer Kim Kardashian, with roughly 1 million followers, was charging around $10,000 to mention a product in one tweet. The paper proposal offers that focusing on one influencer with a huge amount of followers is not necessarily the most efficient strategy.
“Maybe you want to pay your $10,000 but you would rather find 1,000 people who have 1,000 followers each,” said Watts. “And they might do it for free. Or they might do it for $1. So then you pay $1,000, and you still reach a million people.”
The three main findings of the paper are as follows: 1. It is nearly impossible to predict, with accuracy, the efficacy of influence 2. To the extent that one could predict it, “it’s all baked into the past success of the person who seeds the information, and most of it is just how many followers you have,” said Watts
And the 3rd:
“Under a broad range of conditions, you’re actually better off going with a large number of people who have not that many followers, then a small number of people with a large number of followers,” said Watts. “And I think each of those findings has sort of reverberated.”
Rising junior Lejia Zhao is helping to strengthen CIS’s global connections: virtually working with professor Tang Kuk Zuea from the National University of Singapore on a project titled “Using Machine Learning for Medication Recognition” via Penn’s Global Research & Internship Program (GRIP).
Lejia says applying to GRIP was important to her because of her interest in examining computer science through a global lens, and discovering what’s on the forefront in the field, all over the world.
“What further propelled me to move forward with the program after being accepted was the opportunity to practice my intercultural skills,” said Lejia. “I believe that in this increasingly globalized world the ability to work with people from different cultures and experiences is crucial – both on a personal level and a societal level.”
In addition to the program’s noted flexibility, allowing her to pursue other interests and maintain balance, Lejia says the program also provides an opportunity to connect with a computer science student community outside of Penn.
“Another aspect of the program I’ve really enjoyed is getting to know my peers who are also in the GRIP program and even students from other schools who are also doing research at NUS,” said Lejia. “I’ve gotten in touch with Jennifer, a rising sophomore at Johns Hopkins University who is in the same research project as me working under the supervision of Professor Tang.”
When Associate Professor Joseph Devietti was an undergrad in the Department of Computer and Information Science almost 20 years ago, the pace and scale of the department was drastically different.
“Everything has just gotten so professionalized and competitive. Computing has kind of exploded, across campus,” said Devietti. “Things like the second major from the college is really exciting. To be able to give people other ways into computer science, without having to be an engineer and take physics. Follow that kind of rigid path.”
Now the coding aficionado has come full circle as he takes on the role of CIS Undergrad Chair.
“I think the undergrads that we have at Penn, even back when I was here a long time ago, were really strong,” said Devietti. “I’m glad I don’t have to compete with the undergrads that are here now.”
After majoring in both English and Computer and Information Science at Penn, Professor Devietti went on to get both his Master’s and his Ph.D. in Computer Science and Engineering at the University of Washington. With a slew of honors, awards and publications under his belt, CIS Department Chair Zack Ives also notes he is “renowned for his research in using both hardware and software techniques to simplify multiprocessor programming, [and] has also been a successful entrepreneur and an amazing mentor to many undergraduate, Master’s, and PhD students.”
Professor Andreas Haeberlen, whose shoes Professor Devietti will be stepping into, did wonders while serving as chair.
“One of the things I found inspiring about what Andreas had done in his time as undergrad chair was that he had helped a lot with kind of smoothing out these internal business processes,” said Devietti.
In addition to digitizing many paper processes, Professor Ives says Haeberlen also “led curriculum reform across our multiple degree programs [and] personally developed important infrastructure, including the waitlist system that allows us to manage student demand in a fair way.”
With returning to campus and the subsequent readjustment as a top priority, and the nearly 1,000 undergrad students currently enrolled in CIS, Professor Devietti believes the key lies in continuing to focus on efficiency.
“We need to try to streamline things as much as possible,” said Devietti. “I’ve been talking with the advising staff. There are other kinds of opportunities to just help things work more smoothly.”
Professor Tal Rabin is one of the latest researchers to receive ACM’s 2021 STOC Test of Time Award. Co-published with her then Ph.D. advisor, Michael Ben-Or, Professor Rabin’s “Verifiable secret-sharing and multiparty protocols with honest majority” (STOC 1989) was one of three papers to be recognized for its groundbreaking contributions 30 years later.
This year marks the inaugural issuing of the award by ACM’s Special Interest Group on Algorithms and Computation Theory (SIGACT), which recognizes papers published in the Proceedings of the Annual ACM Symposium on Theory of Computing.
Described by Forbes as “a genius for working relationships, which she applies to algorithms as well as team building,” Professor Rabin used a shared attribute of working society to describe the paper’s thesis.
“Let’s say there are three people and together we want to find out what is the sum of all our salaries, but I don’t want to tell you my salary,” said Rabin. “You don’t want to tell me your salary and we don’t want to tell the third person our salary, but still we want to know the sum of all three salaries. How do we compute functions here?”
With the function representing the sum of all individual salaries, Professor Rabin’s hypothetical asserts that previous research before her paper could account for 3 faulty parties out of 11, and still provide accurate computations. Professor Rabin’s paper proves that one could get accurate computations with up to 5 faulty parties. One could still calculate the sum of all the salaries, “even if some of the people are trying to foil the computation, or to learn more than what is supposed to be learned,” said Rabin.
Professor Rabin credits this research, in combination with the works of the other two teams awarded with 30-year honor, with opening up the field of information theoretic multi-party computations.
“It opened so many interesting questions of how fast can we compute, how efficient can we be? Can we do some things better?” said Rabin. “These results proved to be fundamental and enabled a lot of growth afterwards.”
According to Professor Rabin, the paper is not only responsible for laying crucial foundations in the computational theory field, but also in her own professional and private life.
“I’m so honored and happy to be in this group,” said Rabin. “I wrote to Michael, ‘thank you really for suggesting this problem to me.’ I wrote to him, ‘it really defined my life. It impacts my life in a very profound way.’”
According to their site, “Minchen’s dissertation presents a breakthrough in the notoriously challenging and long-standing problem of robust frictional contact simulation in nonlinear solid dynamics with guarantees of non-intersection.”
Minchen describes his project in more practical terms.
“My thesis is about solid simulation: simulating solid interactions,” said Li. “For example, when we want to simulate how a garment will look and feel when dressed up on a person for virtual try-on or digital fashion design applications, we need to model the interactions between the garment and the body, and also the self-contact of the cloth in the knots and pleats regions.”
The proposed framework is not only beneficial in the world of visual effects and animation, but also “essential for industrial design, robotics, mechanical engineering analysis, etc.,” as stated in Minchen’s abstract. ACM SIGGRAPH has recognized the work as particularly exceptional because while past research has offered mere trade-offs between efficiency and physical correctness, “[Minchen’s] approach combines a geometrically exact formulation for collision gap functions, a smoothed friction formulation making it possible to cast it in variational form, and the use of a barrier-based interior point method for optimization.”
Professor Norman Badler, who is set to retire this year after almost 5 decades with CIS, also received a prestigious ACM recognition: he was elected into the 2021 ACM SIGGRAPH Academy Class. Professor Badler was also on the thesis committee for Minchen.
”Norm is very friendly and kind, and also very inspiring,” said Minchen. “ When I showed him the simulation I got from my method, he was very excited and encouraged me forward, and also provided me [with] very constructive ideas.”
To read more about our graduating postdocs and Ph.D. students, including Minchen’s full abstract and plans for after graduation, visit our “Graduating Ph.D.s + Postdocs” site.
The retiring CIS professor chats about his recent ACM SIGGRAPH election and his expansive computer graphics path
Norman Badler’selection into the 2021 ACM SIGGRAPH Academy Class is right on time. After nearly 5 decades of teaching and trailblazing in the Penn community, the Rachleff Family Professor in the Department of Computer and Information Sciences is set to retire later this year.
When he arrived at the University in 1974, CIS itself was only about 2 years old, and there was virtually no computer graphics focus or program at all. Professor Badler had no intention to teach it.
“At that time, I was actually a computer vision researcher, but I was also working a little bit in natural language,” said Badler. “So I was literally brought in to fit between the chair, Aravind Joshi, who was a natural language person, and the computer vision person. It wasn’t until about 3 or 4 years after I came here that I switched over to computer graphics. Mostly because there was a vacuum and a need and an excitement.”
Professor Badler thought he was going to be a mathematician when he chose to attend undergrad at the University of California. He just happened to find work as a computer scientist during freshmen year.
“So when I went to graduate school at the University of Toronto, I went into computer science and I hooked up with computerization and the computer graphics people there,” said Badler.
“And I really learned graphics from an artist who was on the faculty. He was a very interesting, early pioneer in using computer graphics to make art. I think that planted some of the seeds for my interest in combining computer graphics with other fields.”
Several years after completing his dissertation in computer vision and forming a career path to head in that direction, Professor Badler “started getting serious about computer graphics.” An organization that was getting its start around the same time as his Penn career would play a major role: ACM SIGGRAPH (the Association for Computing Machinery’s Special Interest Group on Computer Graphics and Interactive Techniques).
The annual SIGGRAPH conference was held in Philadelphia in the year of 1976, and Professor Badler took full advantage.
“My job for that conference turned out to be to organize the tutorials,” said Badler. “One of the hallmarks of the computer graphics community was the homogeneity caused by its heterogeneity. There were no boundaries. It was just as important to educate new people as it was to learn what the top people were doing. That was a very exciting environment.”
In 1978, Professor Badler was elected the vice chair of SIGGRAPH. It meant an even more central organizing position, and more close contact with other computer graphic scholars.
“That cemented my role and needs to find an academic community. I stayed active in SIGGRAPH for a few more decades after that.”
Getting elected to the ACM SIGGRAPH Academy Class is one of the highest honors in the field of computer graphics. Penn even has its own SIGGRAPH chapter. But Professor Badler’s tenure at Penn also included serving as the founding Director for several centers within computer graphics, including the Center for Human Modeling and Simulation (HMS).
“In the 80s and early 90s, the computer graphics group here that I was leading became famous for building software for modeling human beings,” said Badler. “For engineering purposes, like building interiors of cars that people could fit in, or factories where they could do their jobs safely.”
“By 1996, the Center for Human Modeling had grown to be, essentially, a small business inside the computer science department. Our software was being used around the world.”
When that software, called Jack ergonomics simulation software, was sold in 1996, Professor Badler began exploring connections outside of computer graphics.
“I started interacting with a colleague of mine in Anthropology named Clark Erickson,” said Badler. “We started talking and we thought it would be fun to teach a class that was based on the principles and ideals and problems of Anthropology, but that taught students how modern computer graphics and visualization tools worked, and actually make them use those tools.”
“Neither of us knew what we were doing because we had never co-taught a course with a field anthropologist who was also a museum curator, and here I am, a technologist.”
“It’s just been a terrific experience. It’s been loads of fun, and we are so proud of what our students do,” said Badler. “They can write essays about cultural and gender biases in ancient societies, while at the same time they’re building 3D models of artifacts that are housed in the University Museum. This led to the formation of the ViDi Center.”
“The ViDi Center” became a more popular term of endearment derived from the more technical title of Center for Digital Visualization. Professor Badler has served as founding Director since its inception.
“In order to make a cute title, I actually reversed the ‘Visualization’ and the ‘Digital’, so it became ‘ViDi,’ said Badler. “’Vidi’ is Latin for ‘I saw.’ So there’s a Latin pun in there.”
Rooted in the collaboration between Anthropology’s Clark Erickson, the notable work Badler had done with his wife Virginia in archaeology, and other projects within the humanities, the ViDi Center developed into a cross-disciplinary staple at Penn.
“It turned out that it was a very good vehicle for our undergraduate students in particular to give them context for using computer graphics to create interesting 3D models,” said Badler. “On the ViDi website, a few of those include a 3D model of ENIAC as it was constructed in the Moore School, and we built a complete 3D model of Reading Terminal Market. We used that model for a few research projects because it was extensive, it was interesting, it was cluttered.”
This Summer, members of the ViDi Center are slated to assist an art history professor in reconstructing a Croatian Medieval church.
“We’re a little bit more well-known as a source of capable hands,” said Badler. “Because we don’t actually do the work for these people, but we provide resources so that they can do what they want.”
In addition to computer graphics, Professor Badler is also passionate about doggies. His Dachshunds specifically.
“When you’re an academic, you write like an academic,” said Badler. “A lot of it is really dry and formulaic. And I wanted to write something that was more from the heart,” said Badler.
After about 4 weeks, and some heavy editing and input from his wife, the book was published.
“It was a very important, personal thing for me to write,” said Badler. “I had not written anything for fun since maybe high school.”
Plans for retirement don’t include writing any more books about dogs, more than likely. There are a few projects to wrap up, a PhD student he needs to make sure successfully crosses the threshold. But Professor Badler is not worried about the Department of Computer and Information Sciences. He believes its future lies in capable hands and has a few hopes.
“The only thing I really want to see is another tenure track graphics person hired because we have such a legacy here and such a well-oiled organization. It really needs to be continued, fostered, expanded and maintained,” said Badler. “I’ll continue to do what I can to encourage Zach and the Dean to capitalize on this 47-year investment that they made in me.”
In January 2022, the Comp Info Sci department will welcome Andrew Head as an Assistant Professor. Andrew, who will be starting a Penn HCI (Human Computer Interaction) Group with associate new hire Danaë Metaxa, mainly focuses on helping others express their work fluidly and efficiently.
“My particular sliver of Human Computer Interaction: I work on designing interactive systems that help scientists, and data scientists and programmers,” said Head. “Essentially I want to improve the interactions that we have to support programming, writing and the sharing of expertise.”
Andrew first discovered his interest in HCI soon after graduating college and realizing that the prevailing field of technical learning tools was kind of lacking.
“When I started out with my PhD, I really wanted to be able to equip people with better tools to be able to communicate the learnings that they got from their everyday work — with other people,” said Head. “I see each of the projects that I work on as being this different incarnation of this basic idea: how can we help people work together with computers, who know about their work, and what went into it, and the history of it, and all the little dependencies between it, and be able to shape it up in a form and be able to share it with other people and empower them.”
One example Andrew gives the example is a recent project he worked on that allowed people who built video games to deconstruct the code, and augment it with input and explanations, in order to teach others how they did it.
In addition to the appeal of all sharing resources with the renown faculty already teaching in the department, Andrew also decided to join the Penn team because of his desire to literally teach his passions to others.
“I know from talking with a bunch of the students, there’s a lot of interest for this style of work,” said Head. “Seeing that it would both be a fertile ground for bringing the things that I really love about research to a broader audience, I knew that there would also be a receptive set of awesome researchers across the department to work on these cross-disciplinary projects.”
Andrew and Danaë also plan to create and HCI speaker series in Fall 2022 so that students across the department can learn more about HCI from active researchers in the field.
When asked what made them passionate about the work that they do, Danaë Metaxa describes an intrinsic calling to look to the needs of those that scientific design and application neglects.
“If you’re the type of person that exists at some of those intersections, as I am, you start to see the ways in which those assumptions that system designers or that developers have made, they don’t serve you.” said Metaxa. “You start realizing the limitations of those approaches and the short-sightedness, or even active exclusion, of different types of people. And I think once you notice that, at least for me, as soon as I became attuned to that, it was really hard to look away.”
“In my research, I develop and deploy methods for studying bias and representation in algorithms and algorithmic content, focusing on high-stakes social settings like politics and employment, and on the experiences of marginalized people,” according to Metaxa’s professional site. “The work I do spans identifying biases in existing systems through building interventions or new systems that try to remedy some of those.”
While at Stanford, they were advised by a computer scientist as well as a communications scholar while completing their P.h.D., and will take on a secondary appointment in the Annenberg School for Communication when they start in the Fall. Metaxa cites Penn’s cross-curricular emphasis as a huge factor in deciding to join the Comp Info Sci team.
“I think there’s a lot of places that talk about interdisciplinarity, but there aren’t as many that follow that up in their actions, and show that that’s actually a central value,” said Metaxa. “Something that I’ve loved as grad student at Stanford has been just the strength of the other students around me, even when they do things that are totally different from what I do, because it lets me learn and grow in new and unexpected ways. And Penn — the overall multifaceted strengths of the University — have been a big appeal for me.”
Going forward, in addition to designing a series of HCI classes for the Penn community, Metaxa also plans to engage more with the practical applications of these technologies in the political sphere.
“I think that, unfortunately, there’s a lack of technical expertise in a lot of our government,” said Metaxa. “So it’s really important that lawmakers and policymakers have technologists to work with, and also, as technologists, that we have that broader impact lense, and consider the political and social and environmental context of the work that we do.”
“We are excited to announce the Spring 2021 winners for the Outstanding TA Awards! We are continually amazed at the level of dedication from our TA staff at MCIT Online, we truly appreciate their contributions in delivering a supportive experience for our students. As selected by their students, peers and faculty, please join us in congratulating this semester’s Outstanding TAs for their commitment in leadership and student support. We thank you for a great semester!”
Annual awards are given to undergraduate and graduate students in the Department of Computer and Information Science in recognition of outstanding scholarly achievements and service to the School of Engineering and Applied Science and University community. Departments select each recipient and students are recognized at the Annual Awards Recognition Dinner held during the spring semester. Students also select faculty recipients of the annual Penn Engineering Teaching and Advising Awards each year.
The Department is proud to present its 2021 recipients!