Psychological Test and Assessment Modeling: Ordinal Difference Scaling allows to measure emotion intensity on a metric scale level for most individuals. As a consequence, quantitative emotion theories become amenable to empirical test on the individual level using indirect measurements of emotional experience, Dres. Martin Junge and Rainer Reisenzein (University Greifswald) found in a new study (published in Psychological Test and Assessment Modeling).
"A direct implication of the finding that indirect scalings of emotion intensity have not only a high reliability but also seem to attain a metric scale level is that it is possible to empirically test quantitative emotion theories using indirect scalings of emotion intensity. This conclusion is supported by the previous finding that, compared to direct ratings, indirect scalings of the intensity of relief and disappointment, as well as disgust, yielded substantially improved fits to quantitative models of these emotions.
The present findings suggest that this improvement was partly due to the attainment of a metric (or close to metric) scale level, in addition to the reduction of random error. Because of their higher scale level and greater precision, indirect emotion intensity measurements invite the testing of emotion theories on the individual level. Given that most psychological theories are formulated on the individual level, this is where they should ideally be tested."
M. Junge, R. Reisenzein: Metric scales for emotion measurement. Psychological Test and Assessment Modeling 3/2016, pp 497-530