Effect of Case Sample Difficulty and Choice of Rating Scales on Interobserver Variability in Receiver Operating Characteristic Experiments

摘要: We evaluated the effect of case sample difficulty in receiver operating characteristic (ROC) experiments using both discrete and continuous rating scales, by analyzing data from same set observers at three different levels image-reading difficulty. Simulated computed radiographic mammograms were used as samples. Our experimental results show that averaged Az values essentially identical with scales. When we scale, significance tended to be lower than those raising possibility tests based on scale may more statistically valid.