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: Mathematical Logic plays an important role in many areas of study, including Artificial Intelligence, Philosophy, and Linguistics. Yet students and users of mathematical 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 most 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 has weaknesses as well: an important challenge is to minimize textual ambiguities (e.g., when a sentence is produced that can be parsed in two different ways). The project will focus on First-Order Predicate Logic in the first instance, and on producing explanations in English. Results in an additional language (e.g., Chinese or Dutch, both of which are studied actively in the department) will be welcome.

Project results may include: (1) Algorithms for finding the simplest formula equivalent to a given input logical formula (possibly given some background axioms). (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 background axioms, 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 logic.

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), and others where and when desirable.

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 Faculty of Science from the Utrecht University consists of six departments: Biology, Pharmaceutical Sciences, Information and Computing Sciences, Physics and Astronomy, Chemistry and Mathematics. The Faculty is home to 6500 students and nearly 1500 staff and is internationally renowned for the quality of its research. The Faculty’s academic programmes reflect developments in today’s society.

The Department of Information and Computing Sciences is nationally and internationally renowned for its research in Computing Science and Information Science. Current research groups are Algorithmic Data Analysis, Algorithms and Complexity, Decision Support Systems, Simulation of Complex Systems, Geometric Computing, Multimedia, Human-Centered Computing, Social and Affective Computing, Visualisation and Graphics, Interaction Technology, Process Management and Analytics, Organization and Information, Natural Language Processing, Intelligent Systems, Data Intensive Systems, Software Technology and Software Technology of Learning and Teaching. Relevant areas of interdisciplinary research include Artificial Intelligence, Game Research, Foundations of Complex Systems, Applied Data Science and Integrative Bioinformatics. The Department has close collaborations with the University Medical Center, the Departments of Physics and Mathematics, and the Faculties of Humanities and Geosciences.

For further details, please click here.

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 April 2020), 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  First-Order Predicate Logic.
  • Language: Excellent command of English, together with good academic writing and presentation skills.

Desirable skills:

  • Experience with automated logic theorem proving would be beneficial.
  • 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: 1st April 2020

Contract: Full-time contract

Duration: 36 months, including 3 secondments of 3 months each, at other consortium members’ premises (see the Secondments section above).  

Further information: In line with Dutch regulations, the ESR will be appointed for 4 years, with the fourth year being funded by the Utrecht University.

Salary: Salary starts at € 2325,- gross per month and increases to € 2972 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. More information is available on the website.

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: February 14, 2020, at 23h59 CET (UCT + 01:00)

Enquiries about research content must be sent to the main PhD supervisor via email (see contact details in Supervisors section).