Untangling Complex Systems: The Clauset Lab

From the complicated web of scientific knowledge to interactions among entire species, complex and interconnected systems are all around us. 

Understanding cause and effect in such intricate systems could mean real benefit and impact, but how do you approach it? That's where Professor Aaron Clauset's lab comes in.

"We want to understand how we can untangle the causal mess that makes complex social and biological systems so interesting and important,” Clauset said. 

The lab, Clauset explains, is really three labs in one. 

One group of researchers is building ways to understand huge and complicated data sets that describe complex systems. Many of these computational tools build on advanced techniques from machine learning. 

Other researchers apply those tools to social or biological systems. This often means pairing researchers in the lab with domain experts to understand what methods are needed to tackle a field's most pressing problems. 

Let's learn more about what some of the lab's researchers are up to, and the impact their work is having. 

Katie Spoon (Fourth Year, PhD, Computer Science)

Katie Spoon, who is co-advised by Associate Professor Daniel B. Larremore, has just wrapped up two large research projects on faculty retention. Spoon and her co-authors first used a supercomputer to examine the employment records of nearly 250,000 tenure-track and tenured professors in the United States over the past 10 years.

When Spoon found that there were significant demographic differences in retention, the team expanded the research and conducted a large survey to understand why women were more likely to leave at every stage of their academic career, including as tenured, full professors. They found a tale of harsh workplace conditions and unequal expectations. 

They then conducted a large qualitative follow-up study of some of their respondents, who wrote short stories about what needed to change about their jobs.

The teams' findings were so compelling that Spoon and Clauset were asked to speak with the Office of Faculty Affairs on how the research could improve the experience of faculty at CU Boulder. 

Spoon says she feels grateful that the Clauset lab recognizes the value of a wide range of experimental tools. 

"It's interesting to be doing qualitative analysis in a computer science department,” she said. “There's a lot of freedom to explore new methods."  

Spoon also appreciates that Clauset has encouraged her interests. When she started taking classes in the School of Education, he suggested that she expand it into a master's degree in education policy. 

Nick LaBerge (Fifth Year, PhD, Computer Science) 

Nick LaBerge, who is also co-advised by Larremore, was a physics undergraduate student, but found himself drawn to the more human side of science for his PhD. 

"I'm particularly interested in understanding how the demographic composition of scientists might impact what types of scientific research questions are asked and eventually answered," he said. 

A recent project LaBerge worked on investigated how the different subfields of computer science attract different demographics. 

"What we found is that there are substantial gender differences across computing subfields, and that brings up a lot of questions I'm excited to focus on in the future," he said. 

LaBerge said he deeply appreciates the enthusiasm and collaboration he feels in the lab.

He also enjoys the lab's regular workshops on the research process. "It's important to understand our disciplines well, but there's also the curriculum of how to be a scientist, and that's really valuable to me."

LaBerge was drawn to the Clauset lab because through the science of science, he gets to study how to make science more efficient and more diverse. 

"I've really enjoyed the process of developing as a scientist, and it's meaningful to me that by researching trends in demographic diversity among scientists, we may find ways to make this career path more accessible to a broader range of people," he said. 

Lucy Van Kleunen (Sixth Year, PhD, Computer Science)

Lucy Van Kleunen's research is focused on ecological network analysis. She's co-advised by Assistant Professor Laura Dee in the Department of Ecology and Evolutionary Biology in the College of Arts and Sciences. 

Van Kleunen is currently in Lille, France, where she's working with ecologists who collected plant pollinator data on French grasslands.

She's able to use the data to simulate networks of species. This allows her to simulate the impacts of a disruption, such as a species extinction. She's also working on advanced machine learning methods for predicting missing links in networks. 

"I'm using methods from network science and machine learning to use partially resolved ecological networks and try to predict some of the missing links in them to fill them out," she said. 

Van Kleunen said that she appreciates how interdisciplinary the lab is. 

"People are working in a lot of different domains, and it's useful being able to hear about those other domains and methods that are applicable and then try to think about how that would work in biological networks," she said. 

Van Kleunen said she believes people considering a PhD should find a supervisor and a group that makes you feel excited about doing science and that you think will be supportive. 

"I've really benefited from Aaron letting me explore and pursue collaborations outside of the lab," she said. 

Sam Zhang (Fifth Year, PhD, Applied Mathematics)

Sam Zhang studies social institutions, such as science and academia, to try to understand how underlying factors like social inequalities impact what does and doesn't get investigated. 

"We're combining tools from many different disciplines to understand facts about our reality that could make the world better," Zhang said.

Zhang recently worked on a project to investigate why faculty at elite universities are more productive. He and his collaborators found it's at least partially due to the abundance of available funded research labor at elite universities.

Zhang said he feels like he's found his intellectual home. 

"The lab is so collaborative and interdisciplinary and has given me this very utopian vision of what academia could be like," he said. 

He also admires the working relationship that Clauset has with Larremore. 

"It's an inspiration. They show us that scientists can be open with each other and have lasting friendships and collaborations that go on for decades," he said. 

Zhang recommends that people who might be interested in a PhD explore broadly first. 

"People often have a first love in science and don't realize so much of science would be as attractive to them if they had come across that first," he said. "Giving yourself that time to explore can help draw connections later on during your research."