Measuring art: Methodical development of a quantitative rating instrument measuring pictorial expression (RizbA)

The preliminary version includes 26 items. Its ability for differentiation between pictorial works ranges between .897 (T1) and .766 (T2), its inter-rater reliability between .525 (T1) and .917 (T2). Test-retest reliability is .919. PCA suggests a four-factors solution, which in large part is consistent across studies. As a reliable measurement RizbA opens new perspectives in fundamental art therapeutic and psychological research.