Evaluating the Equal-Interval Hypothesis with Test Score Scales

Author/s: 

Ben Domingue

Year of Publication: 
2014
Publication: 
Psychometrika
Volume/Issue: 
79(1)
Pages: 
1-19

The axioms of additive conjoint measurement provide a means of testing the hypothesis that testing data can be placed onto a scale with equal-interval properties. However, the axioms are difficult to verify given that item responses may be subject to measurement error. A Bayesian method exists for imposing order restrictions from additive conjoint measurement while estimating the probability of a correct response. In this study an improved version of that methodology is evaluated via simulation. The approach is then applied to data from a reading assessment intentionally designed to support an equal-interval scaling.

APA Citation

Domingue, B. (2014). Evaluating the Equal-Interval Hypothesis with Test Score Scales. Psychometrika, 79(1), 1-19.