Measuring and Counting

Every morning I squeeze the orange juice ­ two glassfuls ­ one for Claire ­ one for me. Oranges are very much themselves, each orange an individual in size, color, fragrance, softness. I can count oranges. How many shall I get out of the icebox to fill the two glasses? The trouble is that there is no constant number of oranges that makes a glassful. Sometimes it's only three. Other times it can take six. How on earth can I regularize this procedure?

Well, as I am sure you've already guessed, the solution is embarrassingly simple. The store sells oranges in 4 pound bags. No matter how many oranges it takes, the bag always weighs 4 pounds. Now "a pint's a pound the world around" and an orange is about half juice, by weight. By experiment and/or calculation I establish that 2 pounds of oranges make two glassfuls ­ no more no less. This is always so, no matter how few or how many oranges it takes to weigh the 2 pounds.

The result of this abstract science is that I have a simple, fool-proof, infinitely reproducible, inferentially stable rule: "Take one 4 pound bag of oranges out of the icebox and squeeze half of whatever number of oranges happen to be in it." Two glassfuls are always produced - no matter how many or how few the oranges.

Weighing oranges is vastly superior to counting them ­ perhaps not for art or even literature, but certainly for routinely obtaining a glassful of orange juice. But counting each orange is so immediate, so fulsome, so personal, so individually appreciative, so richly qualitative. While weighing bags of oranges is so impersonal, so meagerly singular, so general, so unappreciative of the true unique, individual nature of each orange, so niggardly quantitative. How dare I reduce the lovely, charming, richly multidimensional orange to a mere cold, stingy weight in lifeless, uncaring pounds ­ what a travesty of nature!

But what a triumph for obtaining a glassful of orange juice every time. You might decry my reduction of the gorgeous orange to such a brutal simplicity as its weight. But you have to admit that for routinizing the production of glassfuls of orange juice you will never in a million years invent an approach that is as simple or as reliable. That's the difference between art and science, between counting right answers and constructing measures.

Ben Wright

Measuring and counting. Wright BD. … Rasch Measurement Transactions, 1994, 8:3 p.371

Rasch Books and Publications
Invariant Measurement: Using Rasch Models in the Social, Behavioral, and Health Sciences, 2nd Edn. George Engelhard, Jr. & Jue Wang	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
Introduction to Many-Facet Rasch Measurement (Facets), Thomas Eckes	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	Appliquer le modèle de Rasch: Défis et pistes de solution (Winsteps) E. Dionne, S. Béland
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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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

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