Figure Skating Fairness

The Gold Medal in Olympic figure skating is awarded to the skater with the lowest median rank. Gold Medals in diving and gymnastics are awarded to contestants with the highest trimmed means. Both statistical techniques are attempts to reduce the influence that any one judge has on who wins the competition. The challenge is to increase fairness by counteracting judge bias.

Rasch measurement is a promising solution to this bias problem. It models skater ability to be independent of the judges' idiosyncrasies and the programs skated(technical and free skate). In other words, the skaters' ability measures are adjusted for unique characteristics of the program skated and the severity of the judges. Maverick (biased) ratings are flagged. Their influence on the measurement system can be determined by estimating skater ability measures with and without them. Substantive differences (e.g., in the awarding of medals) are immediately evident to decision makers.

In the 1994 Ladies event, 9 judges rated 27 skaters on each of two tasks (technical program and free skate). These ratings were rank ordered (as the current regulations require), and then the ranking structure was reanalyzed as a partial-credit rating scale. Rasch analysis (with the Facets computer program) produced measures, standard errors, and fit statistics for each skater, task and judge.

Rankings on the technical program (skated first) were considerably less predictable(Outfit mean-square: 1.3) than for the free skate (Outfit: 0.5). This is because the technical program is more difficult to judge. Nevertheless, of all 459 rankings, only 5 were noticeably unexpected, i.e., misfits. These occurred on the technical program when a poorer skater was ranked unexpectedly high by one judge.

Most judges exhibited a high degree of internal consistency (Outfit: 0.5 - 0.8), but the British and Canadian judges were more variable in their rankings than the others (Outfit: 1.2). In fact, there was a tendency toward too little variation in the rankings (Infits: 0.5). This was not surprising given the familiarity of the judges with the competitors, the experience level of the judges, and the psychological pressure on the judges not to disagree with each other.

The judges exhibited a marked lack of consensus for two only skaters, Zhao (Outfit:1.6) and Zemanova (Outfit: 1.7). The judges from Great Britain and the United States ranked Zhao (China) unexpectedly high on the technical program, and the Ukrainian judge ranked Zemanova (Czech Republic) unexpectedly high on both tasks. Consequently, the measures for Zhao and Zemanova may be inaccurately high. But this had no practical consequence because these skaters were not medal contenders.

Since most skaters' rankings fit the model, the skaters' ability measures constitute useful indicators of skating ability along the linear scale. According to these measures, the top three skaters in descending order were Kerrigan, Baiul and Chen. In fact, the Gold Medal was awarded to Baiul, the Silver to Kerrigan and the Bronze to Chen. This suggests that detecting and, only if necessary, correcting for bias (the Rasch approach) is fairer than assuming the existence of bias and using a statistical technique to attenuate its effects (the current approach).

Marilyn A. Looney

Dept of Physical Education

Northern Illinois University, Dekalb IL 60115-2854

Figure skating fairness. Looney M.A. … Rasch Measurement Transactions, 1996, 10:2 p. 500

Rasch-Related Resources: Rasch Measurement YouTube Channel
Rasch Measurement Transactions & Rasch Measurement research papers - free	An Introduction to the Rasch Model with Examples in R (eRm, etc.), Debelak, Strobl, Zeigenfuse	Rasch Measurement Theory Analysis in R, Wind, Hua	Applying the Rasch Model in Social Sciences Using R, Lamprianou	El modelo métrico de Rasch: Fundamentación, implementación e interpretación de la medida en ciencias sociales (Spanish Edition), Manuel González-Montesinos M.
Rasch Models: Foundations, Recent Developments, and Applications, Fischer & Molenaar	Probabilistic Models for Some Intelligence and Attainment Tests, Georg Rasch	Rasch Models for Measurement, David Andrich	Constructing Measures, Mark Wilson	Best Test Design - free, Wright & Stone Rating Scale Analysis - free, Wright & Masters
Virtual Standard Setting: Setting Cut Scores, Charalambos Kollias	Diseño de Mejores Pruebas - free, Spanish Best Test Design	A Course in Rasch Measurement Theory, Andrich, Marais	Rasch Models in Health, Christensen, Kreiner, Mesba	Multivariate and Mixture Distribution Rasch Models, von Davier, Carstensen
Rasch Books and Publications: Winsteps and Facets
Applying the Rasch Model (Winsteps, Facets) 4th Ed., Bond, Yan, Heene	Advances in Rasch Analyses in the Human Sciences (Winsteps, Facets) 1st Ed., Boone, Staver	Advances in Applications of Rasch Measurement in Science Education, X. Liu & W. J. Boone	Rasch Analysis in the Human Sciences (Winsteps) Boone, Staver, Yale	Appliquer le modèle de Rasch: Défis et pistes de solution (Winsteps) E. Dionne, S. Béland
Introduction to Many-Facet Rasch Measurement (Facets), Thomas Eckes	Rasch Models for Solving Measurement Problems (Facets), George Engelhard, Jr. & Jue Wang	Statistical Analyses for Language Testers (Facets), Rita Green	Invariant Measurement with Raters and Rating Scales: Rasch Models for Rater-Mediated Assessments (Facets), George Engelhard, Jr. & Stefanie Wind	Aplicação do Modelo de Rasch (Português), de Bond, Trevor G., Fox, Christine M
Exploring Rating Scale Functioning for Survey Research (R, Facets), Stefanie Wind	Rasch Measurement: Applications, Khine	Winsteps Tutorials - free Facets Tutorials - free	Many-Facet Rasch Measurement (Facets) - free, J.M. Linacre	Fairness, Justice and Language Assessment (Winsteps, Facets), McNamara, Knoch, Fan

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