Revisiting the Effect of Varying the Number of Response Alternatives in Clinical Assessment: Evidence From Measuring ADHD Symptoms.

This study illustrated the effect of varying the number of response alternatives in clinical assessment using a within-participant, repeated-measures approach. Participants reported the presence of current attention-deficit/hyperactivity disorder symptoms using both a binary and a polytomous (4-point) rating scale across two counterbalanced administrations of the Current Symptoms Scale (CSS). Psychometric properties of the CSS were examined using (a) self-reported binary, (b) self-reported 4-point ratings obtained from each administration of the CSS, and (c) artificially dichotomized responses derived from observed 4-point ratings.