NSF CAREER Award Further Validates Lewis’ Research in Effective CS Education

8/26/2022 9:29:21 AM Aaron Seidlitz, Illinois CS

Since she was a PhD student at the University of California, Berkeley, Colleen M. Lewis has focused the bulk of her research efforts to teaching methods in computer science – with the ultimate goal of increasing access.

Colleen Lewis
Colleen M. Lewis

The Illinois Computer Science professor has continued that effort here, most recently resulting in a new form of validation. In February, Lewis learned that the NSF CAREER Award will fund her effort for five more years.

This specific project, titled “Physical Representations of Programming Concepts,” seeks to “improve the teaching and learning of computer science (CS).” It will do so by addressing “whether and how high school and college students learn from physical versus written representations of programming concepts.”

Considering that her work, since 2009, has led to this moment, how has she sustained the energy and persistence needed to follow through?

“I consider it an act of love to try and support people in their teaching,” Lewis said. “And with the NSF CAREER Award, I'm excited about the possibility for this work to scale. As I further investigate this topic, I’m certain there will be some nuggets to help students better understand abstract ideas in CS.”

Prior to joining Illinois CS, Lewis served on the faculty at Harvey Mudd College in California – where the focus was primarily on teaching.

From a technical perspective, she came upon a consistent hiccup in CS teaching. Compared to, say, math instruction, CS methodology seemed incomplete.

This isn’t exactly surprising, considering that CS – taught at the college level since the 1960s or ‘70s – is still a relatively new discipline compared to math.

What Lewis found is that math instructors can teach the abstract in a more concrete manner.

“There’s a transition where most disciplines can go from a physical object to pictures of objects, and, finally, they have symbols. If the students aren’t understanding the symbols, they can go back to the pictures. If they're not understanding the pictures, they can go back to the physical object,” Lewis said. “I had this realization in my teaching of Java, that I was giving students the abstract version; or the Java code itself. And I was giving them the picture; that's these memory models that we often draw in classroom. But I wasn't giving them the symbol.

“My classes were so helpful and honest about what was working and what wasn't working. So, I had the opportunity to try and refine this concept to try and make abstract ideas concrete.”

As she continued to consider the goal of comparing and evaluating various methods of teaching CS to students, Lewis came upon another flaw.

This moment came as she primarily taught through the use of Java, which is the programming language of choice by the Advanced Placement Computer Science A (APCSA) course. This is the base level to begin instruction in computer science across the country, but Lewis came to understand that Java is “unequally accessible within the country by race and by class. And women, even if their school offers it, are much less likely to take it.”

Already she has made progress in offsetting this issue through previous research dedicated to a site she called CSTeachingTips.org, and in collaborative efforts with high schools in Los Angeles.

Through the NSF CAREER Award, those efforts will continue to expand. It will support Lewis, as she makes strides in developing relationships with the Chicago Public School System on the same topic.

“Without APCSA as a baseline for your CS background, it’s harder to be successful studying computing at the college level,” Lewis said. "I’m excited at the possibility of partnering with the district team at Chicago Public Schools, to search for a solution.”

As for this work now coming full circle – from the time she started it as a PhD student, to following through with it at Harvey Mudd College to now earning the NSF CAREER Award for it here at Illinois CS – the meaningful nature of this path is not lost on Lewis.

“When I moved from Harvey Mudd to UIUC, I started a new career,” she said. “This is a very different job, and this NSF CAREER Award is a valued part of this career. It’s great to have a project with the luxury of a five-year timespan.”

Already, she led a three-day workshop with APCSA teachers from Chicago Public Schools this July, which was hosted by the Discovery Partners Institute. And Lewis added to her online resources for Java teachers interested in using physical representations in their teaching.