Expeditions in Computer Augmented Program Engineering (ExCAPE)

Dr. Rajeev Alur, the Zisman Family Professor at the University of Pennsylvania in the Department of Computer and Information Science, leads the NSF Expeditions in Computer Augmented Program Engineering (ExCAPE). The goal of ExCAPE is to change the way programmers develop software by advancing the theory and practice of software synthesis.  ExCAPE develops synthesis tools that can assist expert programmers in discovering difficult code and meet challenges in multicore programming. As ExCAPE aims to affect industrial practice, design tools will be developed and evaluated in close collaboration with industrial partners.  

Recently, ExCAPE has been developing Personalized Education synthesis tools such as automatic grading and feedback. The goal of automatic feedback is to provide a meaningful explanation of students’ mistakes. In collaboration with Loris D'Antoni (Penn), Dilip Kini (UIUC), Mahesh Viswanathan (UIUC), Bjoern Hartmann (UC Berkeley), and Sumit Gulwani (Microsoft Research) Alur developed the synthesis tool, called AutomataTutor, which has the ability to answer match a varying version of a problem and highlight part of a question. It uses constraint solvers for personalized and actionable feedback.

The goal of AutomataTutor is to help students learn automata theory and to help teachers prepare exercises and problem sets. It saves teachers from having to grade and has even been found to be better than human grading. Currently, AutomataTutor is used at Penn, UIUC, UC San Diego, EPFL (Switzerland), and Reyjkavic University (Iceland). ExCAPE has conducted a rigorous evaluation of AutomataTutor with 377 students in three university courses. It was found that providing either counterexamples or hints is judged as helpful, increases student perseverance, and can improve problem completion time. The students’ response to the tool has been enthusiastic. 

“I thought the feedback was absolutely excellent.”

“I liked its subtle hints.”

“This is a far superior way of learn new things rather than read about something, I hope this way of teaching will be implemented in all schools.”


  AutomataTutor is free and easy to use. Visit automatatutor.com to find out more.