title: Analysis of variations in contrast-detail experiments.
abstract: Three sources of variability in a contrast-detail (CD) experiment have been quantitated: within-observer variance, between-observer variance, and sample variance. It is concluded that (1) it is more efficient to increase the numbers of replicated images and observers than to increase the number of readings; (2) sampling and between-observer variations are approximately equal; (3) one can expect approximately 10% standard errors in the measured value of threshold detail or threshold contrast in a CD experiment which employs four observers, four replicate image samples, and one reading per observer.
mesh_terms: D008961:Models, Structural; D011856:Radiographic Image Enhancement / Q000295:instrumentation; D013647:Task Performance and Analysis; D014796:Visual Perception; D014963:X-Ray Intensifying Screens