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Updated: Dec 27, 2025

A Protocol for Real-time 3D Single Particle Tracking
Published on: January 3, 2018
Tracking with (Un)Certainty.
Abe D Hofman1,2, Matthieu J S Brinkhuis3, Maria Bolsinova4
1Department of Psychological Methods, University of Amsterdam, 1018 WS Amsterdam, The Netherlands.
A new urn-based tracking system, Urnings, improves upon the Elo Rating System (ERS) for personalized learning by providing standard errors and reducing rating variance inflation in computerized adaptive learning (CAL) systems.
Area of Science:
- Educational Technology
- Psychometrics
- Computerized Adaptive Learning (CAL)
Background:
- Personalized learning is a key goal in educational technology, driving the development of Computerized Adaptive Learning (CAL) systems.
- The Elo Rating System (ERS) is widely used in CAL to track student ability and item difficulty, but suffers from drawbacks like lack of standard errors and rating variance inflation.
- Three statistical issues have been identified as the cause of these ERS drawbacks.
Purpose of the Study:
- To address the limitations of the Elo Rating System (ERS) in Computerized Adaptive Learning (CAL) systems.
- To introduce a novel tracking system, Urnings, that resolves statistical issues in ERS and provides standard errors.
- To enable statistical inference, such as testing for learning effects, within CAL environments.
Main Methods:
- Developed a new tracking system, Urnings, representing persons and items as urns with green and red marbles.
- Urns are updated via marble exchange after each response, with marble proportions estimating ability or difficulty.
- Compared the Urnings algorithm against the Elo Rating System (ERS) using simulation studies and empirical CAL data.
Main Results:
- The Urnings algorithm successfully addresses the statistical issues inherent in the Elo Rating System (ERS).
- Urnings provides known standard errors, enabling robust statistical inference.
- The proposed method demonstrates advantages over ERS in both simulated and real-world CAL data.
Conclusions:
- The Urnings algorithm offers a statistically sound alternative to the Elo Rating System (ERS) for tracking in CAL.
- This new approach enhances the capabilities of personalized learning systems by allowing for reliable statistical analysis.
- Urnings facilitates more accurate measurement of student ability and item difficulty, supporting effective educational technology development.
Related Concept Videos
Uncertainty: Overview
Uncertainty: Confidence Intervals
Uncertainty in Measurement: Accuracy and Precision
Propagation of Uncertainty from Random Error
Propagation of Uncertainty from Systematic Error
Uncertainty in Measurement: Reading Instruments

