Down with latent variables! A geometrical view of psychological and educational measurement

The successful candidate will work in the Research Group of Quantitative Psychology and Individual Differences under the supervision of Francis Tuerlinckx. The group offers an international, productive, collaborative, and interactive environment with about six faculty members and more than 30 graduate and postgraduate students.

The University of Leuven is a research‑oriented institution and is consistently ranked among the top research universities in Europe. Leuven is one of the oldest university towns in Europe, located about 30 km from Brussels. It has a rich history and a uniquely friendly atmosphere.
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Project
In psychological and educational measurement, Item Response Theory (IRT) is the gold standard. IRT relies on statistical models in which an unobservable quantity—the latent variable—represents the ability or trait score. However, this latent variable is not uniquely defined, as an infinite number of transformations are mathematically justifiable.

To address this limitation, an alternative IRT framework based on non‑Euclidean geometry will be studied. In this approach, the ability arises naturally by measuring the distance between test takers in a curved model space along a path or arc, rather than relying on an arbitrarily defined latent variable. This arc‑length‑based method is invariant to the choice of the latent variable. In this project, the mathematical properties, conceptual interpretation, and statistical and computational aspects of the arc‑length‑based ability will be developed.

Profile
We are looking for a highly motivated and enthusiastic candidate with a degree in Statistics, Mathematics, Physics, Engineering, or Behavioral or Cognitive Sciences with a strong focus on mathematics/statistics. Other degrees that imply a profound knowledge of statistics, pure mathematics, and programming also qualify. The applicant should have excellent English communication and writing skills.

Offer
We offer a fully funded, full‑time PhD position for one year, with an expected extension to four years. The position is primarily research‑oriented, but the faculty requires PhD students to complete 120 hours of teaching per year (along with some minor educational duties such as exam proctoring). The salary is competitive and in line with university standards. The successful candidate will join a vibrant, international, top‑level research group.

We offer encouraging daily guidance, excellent research facilities, a conference/travel budget, and a competitive salary with various additional benefits (e.g., holidays, health insurance, transport costs).

The successful candidate will work on the mathematical, conceptual, statistical, and computational foundations of geometry‑based measurement. A substantial part of the research will consist of analytical, coding, and simulation‑based work. The candidate will prepare high‑quality scientific papers, write software, and present research findings at (inter)national expert meetings and conferences.

Interested?
For more information, please contact Prof. dr. Francis Tuerlinckx.
Tel.: +32 16 32 59 99
Email: francis.tuerlinckx@kuleuven.be
Application deadline: Monday, May 4, 2026, 8:00 CET
Job interviews: Tuesday, May 26, 2026 (preferably in person, but online if needed)
Expected starting date: October 1, 2026

Applications should consist of:

• A motivation letter (including contact information of two referees).
• A CV (including copies of diploma certificates and university transcripts).
• A piece of academic work in English (e.g., master’s thesis, paper).

Application materials must be submitted below (in PDF format) before Monday, May 4, 2026, at 8:00 CET. If you are invited for an interview, we may ask you to present the results of a take‑home assignment.

You can apply for this job no later than May 04, 2026 via the online application tool.

KU Leuven strives for an inclusive, respectful and socially safe environment. We embrace diversity among individuals and groups as an asset. Open dialogue and differences in perspective are essential for an ambitious research and educational environment. In our commitment to equal opportunity, we recognize the consequences of historical inequalities. We do not accept any form of discrimination based on, but not limited to, gender identity and expression, sexual orientation, age, ethnic or national background, skin colour, religious and philosophical diversity, neurodivergence, employment disability, health, or socioeconomic status. For questions about accessibility or support offered, we are happy to assist you at this email address.

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