BIRM-RS: response styles on visual analogue scales

Psychometrics
R
Shiny
An extension of the Beta Item Response Model that detects extreme, midpoint and acquiescent responding, with a simulation package and interactive apps.

Interactive app birmrssim on GitHub Preprint

Response styles are systematic tendencies to favour particular regions of a rating scale, regardless of what an item asks. They distort means, variances and correlations and can bias group comparisons.

Visual analogue scales produce bounded continuous data, which standard models for Likert-type items do not fit. Together with Tanja Lischetzke and Mirka Henninger, I extended the Beta Item Response Model (Noel & Dauvier, 2007) so that it captures extreme, midpoint and acquiescent responding at the same time.

Simulation

The model is estimated in Stan. A simulation study on an HPC cluster (Slurm) showed that the parameters are recovered well when a questionnaire contains enough items, including reverse-scored ones. The simulation tools are available as the R package birmrssim, citable via doi.org/10.5281/zenodo.20305322.

Interactive apps

Both apps run in the browser with shinylive, no server needed:

  • BIRM-RS: how person, item and response-style parameters shape the distribution of responses
  • Zero- and one-inflated BIRM-RS: a proof of concept for a proposed extension to responses at exactly 0 and 100

Papers

  • Vollbracht, D., Lischetzke, T., & Henninger, M. (2026). Detecting response styles in visual analogue scales. PsyArXiv. doi.org/10.31234/osf.io/xteku_v2
  • Vollbracht, D., Müller, M., Lischetzke, T., & Henninger, M. (2026). Extreme response style generalizes across Likert-type and visual analogue scales. PsyArXiv. doi.org/10.31234/osf.io/zevb7_v1