Hello there, welcome!

My name is Charles but everyone calls me Charlie. I am a postdoctoral researcher in the Computer Science department at Aalto University, working at the intersection of natural language processing and computing education. I am developping methods and frameworks for aligning language models with pedagogical objectives, with applications in automated programming feedback generation and evaluation, and simulated learners. I focus particularly on lightweight, open models that can be safely deployed in educational contexts.

My PhD dissertation laid the groundwork for this.

Recent News

20th Match 2026
I have succesfully defended my PhD!

5 December 2025
My Ph.D thesis has been accepted for defense! Defense information

15 September 2025
Two papers accepted at SIGCSE TS 2026!

  • Aligning Small Language Models for Programming Feedback: Towards Scalable Coding Support in a Massive Global Course (first author)
  • Fine-Tuning Open-Source Models as a Viable Alternative to Proprietary LLMs for Explaining Compiler Messages (second author)

The first came out of my research visit at Stanford, we also put together a presentation page. The second is a collaboration with researchers at The University of New South Wales.

27 May 2025
Paper accepted at CSEDM 2025: “Reinforcement Learning for Programming Feedback: Aligning Small Language Models Without Human Preferences” (first author).

24 May 2025
Paper accepted at BEA 2025: “Direct Repair Optimization: Training Small Language Models for Educational Program Repair Improves Feedback Abilities” (first author).

2 May 2025
Gave a talk at Berkeley’s ACE Lab on feedback generation with small language models.

1 April 2025
Started a research visit at the Piech Lab at Stanford University (through June 2025).