Open Early Stage Researcher/PhD Position at Universiteit Utrecht (UU), Netherlands, for the NL4XAI project

Reference number: NL4XAI- ESR4

PhD research topic: Explaining Logical Formulas

Objectives: Logical formalisms play an important role in many areas of study, including Artificial Intelligence, Philosophy, and Linguistics. Yet students and users of logic sometimes struggle to grasp the exact meaning of logical formulas. This happens when formulas are very complex, or when they have an unusual structure (for example when they are produced by a computational theorem prover). It also happens when learners are not yet fully accustomed to the conventions employed by the logic (e.g., the meaning of connectives in the so-called paradoxes of material implication).

To investigate how Natural Language Generation (NLG) techniques can be employed to automatically and effectively explain logical formulas to non-experts using texts that are formulated in ordinary language (e.g., in English, Dutch, or Chinese), the candidate will investigate computational techniques for simplifying and translating logical formulas into optimally intelligible NL text, and empirically evaluating the usefulness of the resulting text for users.

A key task is to convert a given formula into a form that makes it intelligible to people, for example by removing parts of the formula that follow from background knowledge, and by exploiting particular strengths of Natural Language. But Natural Language pose problems as well: an important challenge is to minimize textual ambiguities (for example, when a sentence is produced that can be parsed in two different ways). The choice of logical formalism is still open; promising options include First Order Predicate Logic and formalisms in Formal Argumentation. The choice of natural language is open; promising options include English, Dutch, and Chinese, which are all studied in the department.

Project results may include: (1) Algorithms for finding the simplest formula equivalent to a given input logical formula. (2) Algorithms for expressing the content of a (simplified) logical formula in NL text. (3) An interface that allows a user to enter an input formula, and to choose between different simplification/presentation strategies. (4) Evaluation results regarding the effectiveness for human users of the above techniques. One option for evaluation is to test whether the generated translations are understood correctly by users; another is to find out to what extent the generated translations help the user’s overall learning of the logical formalism.

The proposed research combines aspects of computational logic, language, and experimental psychology. Since only few people master all three of these research areas, the precise focus of the project will be chosen in conversation with the successful candidate. The supervisory team will include Kees van Deemter (of Utrecht University) and Jordi Levy (of CSIC’s Research Institute for Artificial Intelligence in Barcelona).

Expected Results:

  • Algorithms for finding the simplest formula equivalent to a given input logical formula, given some background axioms.
  • Algorithms for expressing the content of a (simplified) logical formula in Natural Language text.
  • An interface that allows a user to enter an input formula and background axioms, and that produces different types of Natural Language output (i.e., using a range of simplification strategies).
  • Evaluation results regarding the effectiveness for human users of the above techniques

Host institution: Universiteit Utrecht- UU (Netherlands)

PhD Enrolment: Universiteit Utrecht- UU (Netherlands)

The Department of Information and Computing Sciences is nationally and internationally renowned for its fundamental and applied research in computer science and information science. In our constantly changing (digital) society, the department of Information and Computing Sciences is constantly looking for new, realistic ways to push the boundaries of both science and social application. We contribute to innovative information technologies through the development and application of new concepts, theories, algorithms, and software methods. Relevant areas of interdisciplinary research include Game Research, Foundations of Complex Systems, Applied Data Science, and Artificial Intelligence.

The Department has, among others, close collaborations with the University Medical Centre, the Departments of Physics and Mathematics, and the Faculties of Humanities and Geosciences. The Department offers Bachelor’s programmes in Computer Science and Information Science, and six English language Research Master’s programmes in Artificial Intelligence, Business Informatics, Computing Science, Human-Computer Interaction, Game and Media Technology, and Applied Data Science. High enrolment figures and good student ratings make education very successful. The Department currently comprises 17 Chairs and 109 other scientific staff, including Postdocs and PhD candidates.

At the Faculty of Science there are 6 departments to make a fundamental connection with: Biology, Chemistry, Information and Computing Sciences, Mathematics, Pharmaceutical Sciences, and Physics. Each of these is made up of distinct institutes that work together to focus on answering some of humanity’s most pressing problems. More fundamental still are the individual research groups – the building blocks of our ambitious scientific projects.

Utrecht University is a friendly and ambitious university at the heart of an ancient city. We love to welcome new scientists to our city – a thriving cultural hub that is consistently rated as one of the world’s happiest cities. We are renowned for our innovative interdisciplinary research and our emphasis on inspirational research and excellent education. We are equally well-known for our familiar atmosphere and the can-do mentality of our people. This lively and inspiring academic environment attracts professors, researchers and PhD candidates from all over the globe, making both the University and the Faculty of Science a vibrant international community and wonderfully diverse.

Secondments: The ESR will enjoy two secondments of 2 months each and one inter-sectorial secondment of 6 months at the premises of two project’s members as detailed in the following table.


  • Main Supervisor: Prof. Kees van Deemter, Department of Information and Computing Sciences – Universiteit Utrecht (UU), 
  • PhD Co-Supervisor: Dr. Jordi Levy, Artificial Intelligence Research Institute (IIIA)- Agencia Estatal del Consejo Superior de Investigaciones Científicas (CSIC)

Inter-sectoral Secondment Supervisor:

  • Mr. Neil Burnett, Technology R&D team- Arria NLG Limited (Arria)

General requirements:

  • Mobility: At the time of recruitment, the researcher must not have resided or carried out his/her main activity (work, studies, etc.) in Netherlands for more than 12 months in the 3 years prior to recruitment date. Time spent as part of a procedure for obtaining refugee status under the Geneva Convention is not taken into account.
  • Career: When starting their contract (expected in July 2021), selected researchers should be within the first four years of his/her research careers and not have been awarded a doctoral degree prior to the application.
  • The candidate must be working exclusively for the action

Specific requirements:

  • Degree: Master’s degree in an area relevant to this project – this could be Artificial Intelligence, Mathematical Logic, Computing Science, Linguistics, or Experimental Psychology, providing access to PhD program.
  • Candidate needs to have a good understanding of a relevant logical formalism, for example First-Order Predicate Logic.
  • Language: Excellent command of English, together with good academic writing and presentation skills.

Desirable skills:

  • The ideal candidate should take a strong interest in at least two of the three areas: (1) computer science, (2) natural language, and (3) experimental psychology.
  • Good programming skills.
  • Ability to work independently and as part of a team.
  • Strong motivation to pursue a PhD degree.
  • Strong interest in interdisciplinary scientific work

Estimated starting date: 4th July 2021

Contract: Full-time contract

Duration: From the starting date till 30 September 2023, including 2 secondments of 2 months each and one secondment of 6 months, at other consortium members’ premises (see Secondment section).   

Further information: In line with Dutch regulations, the ESR will be appointed for 4 years, with the time after 30 September 2023 being funded by the Utrecht University.

Salary: Salary starts at € 2395,- gross per month and increases to € 3061,- during the appointment (scale P of the Collective Labour Agreement Dutch Universities).

The salary is supplemented with a holiday allowance of 8% and an end-of-year bonus of 8,3% per year. In addition, we offer: a pension scheme, a partially paid parental leave, and flexible employment conditions. Conditions are in accordance with the Collective Labour Agreement Dutch Universities. The research group will provide the candidate with necessary support on all aspects of the project.

In addition to the employment conditions laid down in the CAO for Dutch Universities, Utrecht University has a number of its own arrangements. For example, there are agreements on professional development, leave arrangements and sports. We also give you the opportunity to expand your terms of employment yourself via the Employment Conditions Selection Model. This is how we like to encourage you to continue to grow.

More information about working at the Faculty of Science can be found here.

Application Documents:

  • Detailed CV in Europass format (template available in the following link) in English, highlighting the merits that are established as evaluation criteria;
  • Scans of BSc and/or MSc transcripts, with certified translation in English (if the degree qualification is not in English or in the language of the hosting country); 
  • A motivation letter in English, highlighting the consistency between the candidate profile and the chosen ESR position/s for which she/he is applying and describing why you wishes to be an NL4XAI ESR to carry out a PhD;
  • Contact details or recommendation letters of two referees in English or in certified translation;
  • Scanned copy of valid identification document;
  • Proof of excellent command of English (e.g., IELTS, TOEFL, Cambridge or equivalent). This is not required in case of native English speakers (i.e., English is your mother tongue).

In addition, you can add any other documents which you find relevant for the applications such as Master thesis, publications or project reports.

Evaluation criteria:

  • Academic background (up to 40 points)
  • Knowledge and specific achievements (up to 35 points)
  • Personal interview, only for candidates achieving a minimum of 55 points (up to 25 points)

Deadline: June 4, 2021, at 23h59 CEST (UTC+2)

Enquiries about research content must be sent to the main PhD supervisor, Prof. Kees van Deemter, via email: 

Candidates are encouraged to contact the NL4XAI Project Manager ( for assistance or for any information related to the application process. When contacting, please indicate the position reference in the subject line.