PhD Defence Xiyuan Gao

We are pleased to announce that Xiyuan Gao will defend her PhD thesis 'Toward pragmatic inference in machines: relation-aware multimodal modeling of sarcasm in conversation' on 11 June 2026 in the Auditorium of Campus Fryslân, Wirdumerdijk 34, 8911 CE Leeuwarden.

It is possible to follow the defence online via the livestream.

Programme:

• 10:30 - Layperson’s talk

• 11:00 - PhD defence

Computers and understanding sarcasm

Human communication involves more than words alone. A sentence like “Thank you for being on time” can express gratitude, but with a flat tone or eye roll, it means the opposite. While people naturally combine words, tone, facial expressions, and context to understand such meanings, current language technologies still rely heavily on text.

This dissertation explores how machines can better understand intended meaning in spoken interaction, using sarcasm as a test case. The research shows that models perform better when they capture how verbal, vocal, and visual signals interact, rather than relying on words alone. It also demonstrates that more data only improves performance when it preserves the cues people use to infer meaning.

In addition, the dissertation introduces a Mandarin multimodal sarcasm dataset, showing that systems trained mainly on English require adaptation to interpret meaning reliably in other languages. Overall, this research contributes to more reliable and accessible language technology that understands not only what people say, but also what they mean.

You can read the entire dissertation here.