Research
I use cognitive modeling, computer simulations of human thinking, to study how people learn, control their attention, perceive time and combine simple building blocks into complex skills, and I increasingly apply what we learn to education.
In cognitive modeling we construct computer simulations of human thought. The goal is to understand human thinking better and to build more rigorously testable theories of cognition. I work primarily with the ACT-R architecture, developed by John Anderson, and with my own extension PRIMs.
My research is driven by a sense of wonder that humans can do almost any new task they are confronted with. Two themes are central:
- Learning: how do people pick up task knowledge from instruction, exploration, examples and imitation, and how do they keep discovering new knowledge under the influence of what they already know?
- Cognitive control: how do we discover the right control structure for a new task, and how do we balance internal control with control derived from the environment?
A complementary thread of my work is methodological: I want to make cognitive modeling more constrained, by letting models learn their own task knowledge and by making real, prior predictions of experimental outcomes rather than post-hoc fits.
Research topics
AI in Education · current focus
Building knowledge graphs from student data, and how personalized practice leads to better learning results.
PRIMs and transfer of cognitive skills
An ACT-R extension that breaks rules into primitive building blocks to explain when training on one task improves another.
Multitasking
Threaded cognition and the problem-state bottleneck: when does multitasking lead to interference, and why do people do it?
Time perception
A model of interval timing in which an internal clock, attention and learning together produce our sense of time.
Inaugural lecture (2010)
Draden door de Geest: how to keep hold of the strings in a world of multitasking. In Dutch, with the original figures.
Main theoretical contributions
- Production compilation. A mechanism for learning new rules in ACT-R: it combines two rules and possibly a memory retrieval into a single new rule (with John Anderson).
- The minimal control principle. People organise their representation of a task so that the amount of internal control they have to exert over it is minimal.
- Threaded cognition. A mechanism that allows a cognitive architecture to do multiple things at once (with Dario Salvucci). More
- A time-perception module. A cognitive module for estimating intervals, designed for ACT-R but adaptable to any architecture (with Hedderik van Rijn). More
- Operator representation for instructions. A flexible, robust representation that can be transformed into procedural skills by production compilation, satisfying the minimal control principle.
- PRIMs. An ACT-R extension that breaks production rules into the smallest possible building blocks, enabling reuse across tasks and providing an account of cognitive transfer. More
- Knowledge graphs from student data. Learning which skills an exercise requires directly from students' scores, and using that structure to personalize practice. More
Skill acquisition
When I started using ACT-R it lacked a plausible mechanism for learning new production rules. During a sabbatical in 1999 I developed production compilation: a single mechanism that specialises general problem-solving strategies (e.g. analogy) into task-specific rules, and which in some models leads to qualitatively different behaviour after enough practice.
First applied to learning the English past tense (Taatgen & Anderson, 2002), production compilation has since been used to model German plural learning, phonetic representations, the balance-scale task, and the Kanfer–Ackerman Air Traffic Controller task, accounting for both aggregate data and individual differences.
Control in dual tasking and complex dynamic tasks
A later thread of this work asked how skill acquisition makes people not only faster but also more robust and flexible. The solution was to abandon strict hierarchical task representations in favour of a weak hierarchy: instructions specify the conditions under which they apply and are organised in instruction sets. This produces a better balance between top-down and bottom-up control, and led to the minimal control principle: people organise their task knowledge to minimise the amount of top-down control required.
Key references
Taatgen, N. A., Huss, D., Dickison, D., & Anderson, J. R. (2008). The acquisition of robust and flexible cognitive skills. Journal of Experimental Psychology: General, 137(3), 548–565.
Taatgen, N. A. (2005). Modeling parallelization and flexibility improvements in skill acquisition: From dual tasks to complex dynamic skills. Cognitive Science, 29(3), 421–455.
Taatgen, N. A., & Lee, F. J. (2003). Production compilation: A simple mechanism to model complex skill acquisition. Human Factors, 45(1), 61–76.
Taatgen, N. A., & Anderson, J. R. (2002). Why do children learn to say "broke"? A model of learning the past tense without feedback. Cognition, 86(2), 123–155.
Learning from instructions
Can a good theory of learning improve real instructional situations? Anderson's algebra-tutor work suggests yes. My own work, funded by NASA and the US Air Force, looked at how people learn from instructions and eventually develop knowledge robust enough to handle interruptions and novel situations. The domain we used was programming the flight management system (FMS) of a Boeing 777.
Standard pilot training has crews memorise procedures as ordered lists of steps. This works poorly: pilots forget infrequent procedures and struggle to adapt them to new circumstances; they are neither flexible nor robust. Our cognitive models suggested a better representation: don't just list actions, also specify the conditions under which each action applies and the effect it should have. Take the first step of a typical procedure:
1. Press the LEGS key.
Augmented with context, the same step becomes:
If you want to go to the LEGS page, press the LEGS key, which will bring you to the LEGS page.
In experiments comparing list and context instructions, people who received the context version learned faster, generalised better to new problems, and pressed the LEGS key significantly less often when it would have been unnecessary. Eye-tracking showed an additional benefit: people who got context instructions performed safety-critical verification checks substantially more often (71% vs. 46%).
Funding
Air Force Office of Scientific Research.
Key references
Taatgen, N. A., Huss, D., Dickison, D., & Anderson, J. R. (2008). The acquisition of robust and flexible cognitive skills. Journal of Experimental Psychology: General, 137(3), 548–565.
Taatgen, N. A., Huss, D., & Anderson, J. R. (2006). How cognitive models can inform the design of instructions. Proceedings of ICCM 2006, 304–309.
Team
Current PhD students
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Ram Eshwar Kaundinya
2024–2028 · Cognitive Architectures for Touch-Based Applications · with Jelmer Borst
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Milan van Maldegem
Transient forgetting in human cognition · with Gido van de Ven
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Remon Nicolai
starts December 2026 · AI and Education · with Hedderik van Rijn
Frequent collaborators
- Jelmer Borst — RUG (former postdoc, now faculty)
- Fokie Cnossen — Institute of AI & Cognitive Engineering, RUG
- Jacolien van Rij — RUG
- Elisabetta Chicca — CogniGron / Bio-Inspired Circuits and Systems
- Dario Salvucci — Drexel University
- Hedderik van Rijn — RUG (Psychology)
Former PhD students
- Yang Ji — contextual learning in PRIMs and early language acquisition (with Jacolien van Rij)
- Thomas Tiotto — neuromorphic computing
- Stefan Huijser — multitasking and mind wandering
- Corné Hoekstra — transfer learning
- Mega Bagus Herlambang — models of mental fatigue
- Menno Nijboer — multitasking
- Ioanna Katidioti — multitasking
- Jelmer Borst — multitasking
- Enkhbold Nyamsuren — models of perception and game play
- Katja Mehlhorn — models of decision making
Former postdocs
- Theodros Haile - AI and Education
- Christopher Stevens — metacognitive models
- Harmen de Weerd — metacognitive models
