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Updated: Nov 14, 2025

A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments
Published on: March 1, 2022
Detecting Heterogeneity of Intervention Effects in Comparative Judgments
Wolfgang Wiedermann1, Ulrich Frick2, Edgar C Merkle3
1University of Missouri, Columbia, USA. wiedermannw@missouri.edu.
Log-linear Bradley-Terry (LLBT) models and model-based recursive partitioning (MOB) help evaluate intervention effectiveness using paired comparisons and rankings. The MOB LLBT approach identifies subgroups with differing preferences and intervention effects, offering nuanced insights.
Area of Science:
- Statistics
- Psychology
- Public Health
Background:
- Comparative measures like paired comparisons and rankings are vital for assessing health states and quality of life.
- Existing models may not fully capture treatment effect heterogeneity in such data.
Purpose of the Study:
- Introduce log-linear Bradley-Terry (LLBT) models for intervention effectiveness evaluation with paired comparison or ranking data.
- Present a combination of LLBT and model-based recursive partitioning (MOB) to detect treatment effect heterogeneity.
- Enable identification of subgroups with differing preference orders and intervention effects on choice behavior.
Main Methods:
- Log-linear Bradley-Terry (LLBT) models were employed.
- Model-based recursive partitioning (MOB) was combined with LLBT to detect treatment effect heterogeneity.
- The MOB LLBT approach was demonstrated using artificial and real-world data examples.
Main Results:
- The MOB LLBT model successfully recovered the true model in the artificial data example.
- In real-world data, LLBT confirmed situational drug-harm trivialization among festival visitors when peer behavior was accessible.
- MOB LLBT revealed this trivialization effect is context-dependent, most pronounced in moderately intoxicated individuals who sought counseling.
Conclusions:
- MOB LLBT models provide more nuanced assessments of intervention effectiveness.
- The approach is applicable to paired comparisons, rankings, and rating data.
- R code examples are provided for implementing MOB LLBT models.
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