Psychological measurement between physics and statistics

Abstract

This contribution discusses the physical perspective on psychological measurement represented by additive conjoint measurement and the statistical perspective represented by item response theory, and argues that both fail to adequately address the real measurement problem in psychology: this is the absence of well-developed theories about psychological attributes. I argue that the two perspectives leave psychology out of the equation and by doing so come up with proposals for psychological measurement that are fruitless. Only the rigorous development of attribute theories can lead to meaningful measurement. I provide two examples of the measurement of theoretically well-developed attributes and suggest future directions for psychological measurement.