Fig. 2From: Validation of the Questionnaire to Identify Knee Symptoms (QuIKS) using Rasch analysisFitting persons and items threshold distribution on the same logit scale. The distribution of the subjects’ estimate of knee symptoms-related experiences is in the upper histogram, with increasing levels of knee symptoms-related experiences from left to right on the x-axis. The lower histogram shows the distribution of the 13 items’ response categories threshold estimates, with higher levels of knee symptoms-related experiences from left to right on the x-axisBack to article page