Be the change that you wish to see in the world. – Gandhi

Hi. I'm Chaiyong Ragkhitwetsagul.

I'm a lecturer at the Faculty of ICT, Mahidol University, Thailand, where I co-founded the SERU research group.

I received my a PhD in software engineering from UCL, where I was a member in the Centre for Research on Evolution, Search and Testing (CREST) under Software Systems Engineering (SSE) group in the Department of Computer Science at University College London.. I received a master degree of MSIT-Very Large Information Systems from Carnegie Mellon University, USA and a bachelor degree in Computer Engineering from Kasetsart University, Thailand.

I'm currently staying in Bangkok, a wonderful city with great foods (but the worst traffic!) ...

Cirriculum Vitae
You can find my CV here:


I host a weekly software engineering podcast (in Thai) called SE Corner. Please check the latest episode below.

Research Areas

My research interest lies in the area of software engineering. Specifically, I am currently interested in these three research topics:

search Code search

My PhD thesis is "Code similarity and clone search in large-scale source code data". I have built a code clone search tool, called Siamese, that is able to query for similar source code snippets from Internet-scale datasets (>100M SLOC) within seconds with high accuracy. I'm also working on applying the tool to check for cloned code from Stack Overflow in software projects.

file_copy Clone Detection

I am particularly interested in clone detection and its related work or applications. I evaluated 30 state-of-the-arts source code similarity analysers against different types of code modifications, the largest study to date (see the paper). Moreover, I've tried using search-based techniques with clones such as optimising clone detection tool's parameters to maximise clone agreemenet among tools (paper)

unarchive Mining of Software Repositories

I am currenlty studying the effects of cloned code between Stack Overflow and open source projects in terms of licensing violation and outdated code (paper).

Latest Updates

  2 October 2022:  Our IWSC '22 paper "BigCloneBench Considered Harmful for Machine Learning" received the Best Paper and Best Presentation award!

  30 July 2022:  Jens and I have a new clone study published at the 16th International Workshop on Software Clones (IWSC '22'). We found problems in the widely-used BigCloneBench dataset when it is used to training ML-based clone detection models. The preprint is here.

  22 June 2022:  The SERU team and the UCL team have successfully organized a sharing lesson learned session which have the 4 companeis that have been working with us in the ASETSI project to share their experiences. Check out the detail here.

  17 December 2021:  The result of the first phase of my Automated Software Engineering for Thailand Software Industry project titled "Identifying Software Engineering Challenges in Software SMEs: A Case Study in Thailand" has been published in the Industry Track of the 29th International Conference on Software Analysis, Evolution, and Reengineering (SANER’22)!

  9 November 2021:  I have received the Research Grant for New Scholar (RGNS) 2021 for 2 years from Ministry of Higher Education Science Research and Innovation (MHESRI) on the topic of "Code similarity applications for improving software quality."

  23 July 2021:  Morakot and I have received an honorable mention for the Learning Innovation for Online Courses Awards in the category "Online Engagement and Motivation Techniques, Innovations and Learning Models" from the Software Design and Development course where we used the VR system (Mozilla Hubs and for student presentations. Short video explaining our teaching method can be found here: [3 minutes] [7 minutes].

  3 October 2020:  The Teddy paper received the "Best Tool Demo Award" from ICSME 2020!

  11 July 2020:  Another paper from my undergraduate students titled "Teddy: Automatic Recommendation of Pythonic Idiom Usage For Pull-Based Software Projects" is accepted for the tool demo track of ICSME 2020!

  4 July 2020:  The paper from student internship at Monash University, titled "JITBot: An Explainable Just-In-Time Defect Prediction Bot", is accepted for the tool demo track of ASE 2020!

  3 February 2019:  My Siamese: Scalable and Incremental Code Clone Search via Multiple Code Representations (EMSE 2019) paper is accepted for the Journal-First Presentation at ICSE 2020.

  1 November 2019:  Four internship students' papers are accepted at IWESEP 2019! See them here.

  29 August 2019:  I presented my Toxic Code Snippets on Stack Overflow TSE paper at ESEC/FSE 2019 (Journal-First Track) in Tallinn, Estonia.

  11 May 2019:  I successfully completed the ISO/IEC 29110 and ISO/IEC 15504 (33000) Expert for Consult, Auditor and Lecture Training Course and passed the qualifying exam with a certification.

  25 April 2019:  The paper I co-authored titled The Impact of Code Review on Architectural Changes is accepted for publication at Transactions on Software Engineering (TSE).

  12 February 2019:  And on the same day, a paper from another research project of Siamese: Scalable and Incremental Code Clone Search via Multiple Code Representations is also accepted for publication at Empirical Software Engineering (EMSE). Way to go!

  12 February 2019:  The Toxic Code Snippets on Stack Overflow research project that I have been doing since I was a PhD student (with several rejections) is now accepted for publication at Transactions on Software Engineering (TSE)!

  4 December 2018:  I was invited to be a program committee of the Technical Research track of the 35th IEEE International Conference on Software Maintenance and Evolution (ICSME 2019).

  22 November 2018:  I was invited to be a program committee of the Technical Research track of 27th IEEE/ACM International Conference on Program Comprehension 2019 (ICPC 2019).

  30 October 2018:  I was invited to be a program committee of the 13th International Workshop on Software Clones (IWSC 2019).

  6 September 2018:  Please consider checking out my recent blog post about my PhD experience: Things I learn from my PhD

  30 August 2018:  I successfully defended my PhD thesis titled "Code similarity and clone search in large-scale source code data."!

  3 Mar 2018:  A co-authored work with master students at UCL titled "Who's this? Developer identification using IDE event data" is accepted at MSR 2018 Mining Challenge track.

  17 Feb 2018:  My paper titled "A picture is worth a thousand words: code clone detection based on image similarity" is accepted at IWSC'18.

  12 Oct 2017:  I am invited as the Publicity Chair of IWSC'18.

  6 Oct 2017:  The paper A Comparison of Code Similarity Analysers, the extension of our SCAM'16 work, is accepted for publication in Empirical Software Engineering.

  17 May 2017:  I passed my Transfer Viva and became a PhD candidate!

  21 Feb 2017:  My paper won the People's Choice Award (i.e. best presentation) from IWSC'17!

  10 Jan 2017:  The paper Using Compilation/Decompilation to Enhance Clone Detection is accepted at IWSC 2017.

  25 Oct 2016:  My SCAM'16 paper is invited for EMSE journal extension.

  12 Sep 2016:  I receive NSF Student Travel Support for my trip to SSBSE'16 in the US. Thanks to the organiser!

  29 Jul 2016:  My submission of Similarity of Source Code in the Presence of Pervasive Modifications to SCAM 2016 is accepted.

  29 Jul 2016:  My submission of Measuring Code Similarity in Large-scaled Code Corpora to late pre-doctoral ICSME 2016 Doctoral Symposium is accepeted.

  30 Jun 2016:  I am awarded a 1-year $20,000-worth cloud computing power from Microsoft Azure for Research for my proposal of "ISiCS: Internet-scaled Similar Code Search".

  23 Jun 2016:  My paper Searching for Configurations in Clone Evaluation: A Replication Study is accepeted at SSBSE'16. I was very excited since this is the first research paper ever in my PhD study.


As an academic partner of Visual Paradigm, Mahidol University has access to the online diagramming tools (e.g. UML, Flowchart, ArchiMate, BPMN, Mindmap, etc) and scrum tools provided by Visual Paradigm.