Seminar: Exams with More Learning and Less Stress with a Computer-based Testing Facility
Craig Zilles
Professor and Severns Faculty Scholar
Siebel School of Computer and Data Science
University of Illinois at Urbana-Champaign
Friday, November 21, 2025
2:30 - 3:45 p.m.
Classroom Building, Room 260
Abstract
Exams are an important tool for summative assessment, whose utility has only grown with the advent of large language models (LLMs) like ChatGPT, because they can be implemented in a trustworthy manner. But exams are generally not well liked by either students or faculty. Students find them stressful. For faculty (and their course staff), they represent a large administrative burden to write, proctor, and grade. This large burden means they are done infrequently in many classes, but this infrequent testing encourages cramming and leads to high test anxiety.
In this talk, I'll share (1) research on the benefits of frequent testing and "second-chance testing" (optional exam re-takes) on increased student learning and decreased test anxiety, (2) research on patterns of cheating on un-proctored online assessments, and (3) how we've reduced the instructor workload at Illinois to implement frequent testing through our Computer-based Testing Facility (CBTF). The CBTF is a collection of proctored computer labs that, in conjunction with the PrairieLearn open-source question-asking platform, enable our faculty to run sophisticated exams with almost no recurring effort even in the largest classrooms. For example, our CS 1 course for majors (run by a single faculty member) ran weekly exams for 1,150 students. Key enabling ideas for the CBTF include: (1) sophisticated auto-grading questions, (2) question generators, (3) asynchronous exams, and (4) dedicated testing space and proctors. The CBTF has been running for over 10 years and proctored over 100,000 exams last semester.
Biography
Craig Zilles is a Professor and Severns Faculty Scholar in the Siebel School of Computer and Data Science at the University of Illinois at Urbana-Champaign. His current research focuses on applying computing and data analytics to education, including the development of the Computer-based Testing Facility (CBTF). Previously, his research focused on the interaction between compilers and computer architecture, and he developed the first algorithm that allowed rendering arbitrary three-dimensional polygonal shapes for haptic interfaces (force-feedback human-computer interfaces). He received the IEEE Education Society's 2010 Mac Van Valkenburg Early Career Teaching Award and an NSF CAREER award. At Illinois, he has received a wide range of teaching awards, including a 2018 Campus Award for Excellence in Undergraduate Teaching, a 2013 Illinois Student Senate Teaching Excellence Award, and the College of Engineering's Rose Award (2007) and Everitt Award (2008) for Teaching Excellence. He holds 5 patents and his research has been recognized by a best paper awards from ASPLOS in 2010 and 2013 and by selection for inclusion in the IEEE Micro Top Picks from the 2008 Computer Architecture Conferences.