The Relation of Mood and Sexual Desire: An Experience Sampling Perspective on the Dual Control Model

Proof of Reliability Convergence to 1 at Rate of Spearman-Brown Formula for Random Test Forms and Irrespective of Item Pool Dimensionality

It is shown that the psychometric test reliability, based on any true-score model with randomly sampled items and uncorrelated errors, converges to 1 as the test length goes to infinity, with probability 1, assuming some general regularity conditions. The asymptotic rate of convergence is given by the Spearman-Brown formula, and for this it is not needed that the items are parallel, or latent unidimensional, or even finite dimensional. Simulations with the 2-parameter logistic item response theory model reveal that the reliability of short multidimensional tests can be positively biased, meaning that applying the Spearman-Brown formula in these cases would lead to overprediction of the reliability that results from lengthening a test. However, test constructors of short tests generally aim for short tests that measure just one attribute, so that the bias problem may have little practical relevance. For short unidimensional tests under the 2-parameter logistic model reliability is almost unbiased, meaning that application of the Spearman-Brown formula in these cases of greater practical utility leads to predictions that are approximately unbiased.

Three Quarks for Hypersexuality Research

In some areas of sex research, we note room for methodological improvement of research practices. In particular, in the field of hypersexuality research, where societal norms have been influential, methodological improvement might advance goals of objectivity in research. We propose that hypersexuality research should: firstly, take into account relevant subpopulations; secondly, use Item Response Theory (IRT) to construct item banks for measurement instruments; and, thirdly, measure sexual desire and related important constructs where and how they play out—in daily life, changing from moment to moment. We show that comparing relevant subpopulations can lead to depathologizing normative, but highly frequent, sexual behavior. Using IRT can lead to more precise measurement instruments by assessment of characteristics of individual items. Measuring sexual desire as an inherently fluctuating process in everyday life, and as part of emotion regulation processes, can direct research towards relevant associations other research methods might miss. Bringing into practice our three proposals for improvement can procure a number of advantages. We illustrate these advantages mainly for the field of hypersexuality research, but our suggestions might also be beneficial for sex research in general.