Fig. 1
From: Measuring self-reported ability to perform activities of daily living: a Rasch analysis
Scatterplot (DTF analysis) of the variance of ability measures across the full (47-item) and reduced (31-item) version of the ADL-I. The model for invariance of measures is represented by a straight line with a slope equal to 1 (i.e. 45°) through the point representing the mean quality of ADL task performance measure from each version. Control lines, representing a 95% confidence interval on either side of the diagonal line, drawn through the mean quality of ADL task performance measures, illustrate quality of ADL task performance measures displaying significant variance across the two versions [23]