Hello! I am a Lecturer (US: Assistant Professor) in the Department of Engineering Mathematics at the University of Bristol. You can contact me at martha dot lewis at bristol dot ac dot uk

Quick links: Publications; Google Scholar; DBLP

Research Interests and Bio

How are humans able to combine concepts to form new ones? Why do unexpected or ’emergent’ attributes arise in these combinations? I am using computational linguistics, conceptual spaces theory, quantum theory, and category theory to try and answer questions like these.

Before Bristol, I held a Veni fellowship at the ILLC at the University of Amsterdam. I was a postdoc in the Quantum Group in the Department of Computer Science, University of Oxford, under the project ‘Algorithmic and Logical Aspects of Meaning’ funded by AFOSR. I did my PhD at the University of Bristol, in the Bristol Centre for Complexity Sciences, and before that the EASy MSc at the University of Sussex.


September 2021 Back in the office and actually met some people in real life at the BIAS summer school – https://www.bristol.ac.uk/cdt/interactive-ai/bias-summer-school/ – a summer school for the Bristol Interactive AI CDT. Talks all online, but we were able to meet for lunch and poster session.

August 2021 ⛱ ⛱ ⛱

July 2021 Michael Moortgat and I are guest editors of the Journal of Cognitive Science (http://jcs.snu.ac.kr/jcs/) with a special issue containing selected extended papers from SemSpace 2020. This was a fun issue to put together – and another will be out in September.

June 2021 SemSpace 2021 went well! Website https://sites.google.com/view/semspace2021/home has all submitted papers, and long papers available in the proceedings here: https://iwcs2021.github.io/proceedings/semspace/index.html. Videos up soon!

I gave a tutorial on quantum theory in natural language processing at QPL – video here: https://www.youtube.com/watch?v=89d7mz11JWA

April 2021 My MSc student Xiaoyu Tong (co-supervised with Katia Shutova) submitted her Masters thesis – she collected a large dataset of metaphor paraphrases, and analysed how people judge the aptness of those paraphrases. The dataset is available here: https://github.com/xiaoyuisrain/metaphor-paraphrase-dataset, together with the report – stay tuned for more work on this!

February 2021 Teaching starts! I’m teaching Introduction to Artificial Intelligence to around 200 MSc students across 4 programmes. It’s a lot of work and a lot of fun 🙂

January 2021 There will be another edition of SemSpace in 2021 (https://sites.google.com/view/semspace2021/home), (virtually) colocated with IWCS (https://iwcs2021.github.io/). I’m co-organising with Mehrnoosh Sadrzadeh again, ably assisted by Lachlan McPheat

December 2020 I will be giving a tutorial on quantum theory in natural language processing at QPL: https://qpl2021.eu/ – wonder if there is a chance of getting there in person??

November 2020 My co-author Francois Meyer presented our work on Modelling Lexical Ambiguity with Density Matrices at CoNLL 2020. This work uses density matrices, from quantum theory, to model multiple senses of a word together in one representation. When the density matrices are combined to for phrases and sentences, the ambiguity is resolved: I went to the bank to deposit a cheque vs I went to the bank to fish

September 2020 Just gave a talk at QNLP as part of Cambridge Quantum Computing’s Quantum Week of Fun. If you want to see me multitasking childcare and talking about density matrices for words, take a look here

I started a new job as Lecturer in the Department of Engineering Maths in the University of Bristol. Unusual start, of course, but so far everyone has been very welcoming.

SemSpace2020 videos now available! Each video is linked on the webpage: https://sites.google.com/view/semspace2020/programme and they are also available on a dedicated YouTube channel:

SemSpace: https://www.youtube.com/channel/UCl3A4-AlVZl_akf4KP6olYg

August 2020 SemSpace2020 went really well. There are definitely some benefits to online conferences, such as coauthors answering questions concurrently in the chat, and ease of making video recordings available. Speaking of which, videos for all talks will be up soon…

I have been invited to give a talk at the second QNLP conference (link to first). This was super fun last year, looking forward to this one!

July 2020 Slides for my talk ‘Towards logical negation for compositional distributional semantics’ are available here. The paper is available at https://arxiv.org/abs/2005.04929

June 2020 My paper ‘Towards logical negation for compositional distributional semantics’ was accepted for a keynote talk at ACT2020.

May 2020 Gemma De las Cuevas, Andreas Klingler, Tim Netzer, and I put a new paper up on the arXiv: Cats climb entails mammals move: preserving hyponymy in compositional distributional semantics, https://arxiv.org/abs/2005.14134. This was an outcome of my visit to Innsbruck last February.

April 2020 Michael Moortgat and I are organising SemSpace2020. If you’re interested in compositionality, reasoning, and logics for vector space models of meaning, please consider submitting a paper! With the COVID-19 situation, the workshop is likely to be online, updates will be posted.

March 2020 Working at home with a toddler is everything you might imagine!

I gave a talk (slides) at the Language in AI symposium for the Bristol Interactive AI CDT. The symposium had such a great range of topics, including AI in Homer’s Odyssey!

February 2020 I visited Gemma de las Cuevas at the University of Innsbrück to talk about my work using positive operators in linguistics. This was a very helpful visit, and hope to write more about the outcome in a while.

December 2019 Talk (slides) at the first Quantum NLP conference organised by Cambridge Quantum Computing and the University of Oxford. This was super exciting, lots of people starting to work on NLP on actual (and simulated) quantum computers!

I attended the Lorentz Center Seminar Logic and Structures in Computer Science and Beyond. Topics ranged from very theoretical computer science through to NLP and cognitive science. Some fruitful discussions on conceptual spaces, hope to have updates in a while…

September-October 2019 My course Conceptual Spaces for AI has been running for the second year throughout September and October. One day I will organise and post the content publicly. It has been great fun giving the course this year, lots of updates to improve the content and delivery style and I think it has paid off.

August 2019 Mehrnoosh Sadrzadeh and I have been teaching the course Vector Space Models of Meaning at ESSLLI 2019. We also (together with Dan Marsden) organised an advanced workshop on Semantic Spaces at the Intersection of NLP, Physics, and Cognitive Science.

May 2019 Invited talk at D-IEP Workshop on Emergence: Language change and concept composition (slides)

April 2019 Invited talk at CRC colloquium seminar: Interacting conceptual spaces (slides)

I’m on the PC for SYCO3, a fantastic forum for all things compositional. Please consider submitting a paper!

The CfP for SEMSPACE2019 has gone out! Please consider submitting a paper.

On the PC for IJCAI2019, 28th International Joint Conference on Artificial Intelligence, held in Macao, China, 10-16 August 2019.

Invited talk at SYCO2: Compositionality in Semantic Spaces (slides)

On the PC for IWCS2019, 13th International Conference on Computational Semantics, University of Gothenburg, Sweden 23-27th May 2019.

On the PC for QPL2019, Quantum Physics and Logic, Chapman University, June 10–14, 2019.

PC member for ACT2019, Applied Category Theory, University of Oxford 15-19 July 2019 – please consider submitting a paper. If you’re a student or postdoc interested in applying category-theoretic  methods to problems outside of pure mathematics, do consider the Adjoint School also!

I’m organising SEMSPACE2019 with Mehrnoosh Sadrzadeh and Dan Marsden – we’re very excited that it’s been accepted as a workshop at ESSLLI2019! Mehrnoosh Sadrzadeh and I are also giving a course on Vector Space Models of Meaning at ESSLLI2019.

Proceedings for CAPNS2018 are out! Available here.

I’m very honoured to be giving a talk at the DIEP Workshop on Emergence.

September 2018 CAPNS2018 was a success! We had a very nice selection of accepted papers, including one arising from my strand of the ACT 2018 Adjoint School: Translating and Evolving: Towards a Model of Language Change in DisCoCat. Thanks Jade Master, Tai-Danae Bradley and Brad Theilman for all the ideas, discussion, and work – to be continued!

I am co-organiser of the Lorentz Center Workshop Applied Category Theory 2018 and a mentor for the ACT 2018 Adjoint School. I’ll be mentoring the strand Compositional approaches to linguistics and cognition.

October 2017  I’ll be speaking at Concept Learning and Reasoning in Conceptual Spaces.

July 2017 I taught the ESSLLI Summer School Introduction to Categorical Compositional Distributional Semantics.

May 2017 I participated in the Dagstuhl Workshop Human-Like Neural-Symbolic Computing.