Gregory Gay

Gregory Gay


Greg is an assistant professor of Computer Science & Engineering at University of South Carolina. He was previously a PhD student and research assistant at University of Minnesota under a NSF Graduate Research Fellowship, working with the Critical Systems research group. He received his BS and MS in Computer Science from West Virginia University.

Additionally, Greg has previously interned at NASA's Ames Research Center and Independent Verification & Validation Center, and spent time as a visiting academic at the Laboratory for Internet Software Technologies at the Chinese Academy of Sciences in Beijing.

When not working towards his degree, Greg writes about open source software, the impact of technology on human rights, video games, and "nerd culture." His work has previously appeared on 4 Color Rebellion, The Escapist, and Your Rights Online, among others.

Research Interests

Greg's research is primarly in the areas of search-based software engineering and automated software testing and analysis, with an emphasis on aspects of the test oracle problem. His current research focus is on construction of effective test oracles for real-time and safety critical systems, including methods of selecting oracle data and making comparisons.

His approach to addressing research problems is based on a data-centric approach, forming an intersection between search, optimization, data mining, and artificial intelligence. He strives to harness the information content of software development artifacts to improve the efficiency and quality of the testing process and to automate tasks in order to lessen the burden on human testers.

His past research has largely focused on the application of search, optimization, and information retrieval techniques to various software engineering tasks, including model optimization, requirements engineering, effort estimation, defect detection, and the traceability between source code and defect reports.


  • PhD Computer Science, University of Minnesota.
    Graduation date: Spring 2015.
    Advisor: Dr. Mats Heimdahl.
    Thesis title: Steering Model-Based Oracles to Admit Real Program Behaviors.
  • M.S. Computer Science, West Virginia University.
    Graduation date: Spring 2010.
    Advisor: Dr. Tim Menzies.
    Thesis title: Robust Optimization of Non-Linear Requirements Models.
  • B.S. Computer Science, West Virginia University.
    Graduation date: Spring 2008.
    Senior project: LOUD Platform.

Interested in Software Engineering?

If you are a USC student (undergraduate, masters, or Ph.D.) interested in topics related to software engineering (especially software testing), feel free to stop by my office to chat. I am looking for students to advise and conduct research with.


  • E-Mail: greg [at] greggay dot com
  • Phone: (803) 777-9479
  • Skype: Greg4cr
  • Address: 3A66 Swearingen Engineering Center,
    University of South Carolina
    Columbia, SC 29201

Documents of Interest



  • Efficient Observability-based Test Generation by Dynamic Symbolic Execution
    Dongjiang You, Sanjai Rayadurgam, Michael Whalen, Mats P.E. Heimdahl, Gregory Gay
    Conference - ISSRE 2015 [PDF]
  • Automated Steering of Model-Based Test Oracles to Admit Real Program Behaviors
    Gregory Gay
    Doctoral Dissertation - University of Minnesota, Spring 2015 [PDF]
  • Automated Oracle Data Selection Support
    Gregory Gay, Matt Staats, Michael Whalen, Mats Heimdahl
    Journal - IEEE Transactions on Software Engineering, 2015 [PDF]
  • The Risks of Coverage-Directed Test Case Generation
    Gregory Gay, Matt Staats, Michael Whalen, Mats Heimdahl
    Journal - IEEE Transactions on Software Engineering, 2015 [PDF]
  • Improving the Accuracy of Oracle Verdicts Through Automated Model Steering
    Gregory Gay, Sanjai Rayadurgam, Mats Heimdahl
    Conference - ASE 2014 [PDF]
  • Steering Model-Based Oracles to Admit Real Program Behaviors
    Gregory Gay, Sanjai Rayadurgam, Mats Heimdahl
    Conference - ICSE 2014 - NIER Track [PDF]
  • Moving the Goalposts: Coverage Satisfaction is Not Enough
    Gregory Gay, Matt Staats, Michael Whalen, Mats Heimdahl
    Winner, Best Presentation Award
    Workshop -SBST 2014 [PDF]
  • Community-Assisted Software Engineering Decision Making
    Gregory Gay, Mats Heimdahl
    Workshop - RAISE 2013 [PDF]
  • Observable Modified Condition/Decision Coverage
    Michael Whalen, Gregory Gay, Dongjiang You, Mats Heimdahl, Matt Staats
    Conference - ICSE 2013 [PDF]
  • Automated Oracle Creation Support, or: How I Learned to Stop Worrying About Fault Propagation and Love Mutation Testing
    Matt Staats, Gregory Gay, Mats Heimdahl
    Conference - ICSE 2012 [PDF]
  • On the Danger of Coverage Directed Test Case Generation
    Matt Staats, Gregory Gay, Michael Whalen, Mats Heimdahl
    Conference - FASE 2012 [PDF]
  • A Baseline Method for Search-Based Software Engineering
    Gregory Gay
    Conference - PROMISE 2010 [PDF]
  • Sharing Experiments Using Open Source Software
    Adam Nelson, Tim Menzies, Gregory Gay
    Journal - Software: Practice and Experience, 2010 [PDF]
  • When to Use Data from Other Projects for Effort Estimation
    Ekrem Kocaguneli, Gregory Gay, Yim Menzies, Ye Yang, and Jacky Keung
    Conference - ASE 2010 [PDF]
  • Automatically Finding the Control Variables for Complex System Behavior
    Gregory Gay, Tim Menzies, Misty Davies, and Karen Gundy-Burlet
    Journal - Automated Software Engineering, 2010 [PDF]
  • Measuring the Heterogeneity of Cross-company Datasets
    Jia Chen, Ye Yang, Wen Zhang, Gregory Gay
    Conference - PROFES 2010 [PDF]
  • The Robust Optimization of Non-Linear Requirements Models
    Masters Thesis - WVU, Spring 2010 [PDF]
  • Finding Robust Solutions in Requirements Models
    Gregory Gay
    Journal - Automated Software Engineering, January 2010 [PDF]
  • On the use of Relevance Feedback in IR-based Concept Location
    Gregory Gay, Sonia Haiduc, Andrian Marcus, Tim Menzies
    Conference - ICSM 2009 [PDF]
  • How to Build Repeatable Experiments
    Gregory Gay, Tim Menzies, Burak Turhan, Bojan Cukic
    Conference - Promise 2009 [PDF]
  • Implications of Ceiling Effects in Defect Predictors
    Tim Menzies
    Conference - Promise 2008 [PDF]

More of Greg on the Internet