Figure 12

Two-parameter item-response theory curves for the seven stations. The left-most curves are for the Clear Fail – Fail borderline, the middle curves for the Fail-Pass borderline, and the right-most curves for the Pass-Clear Pass borderline. The two communication stations are shown as solid lines (Black: Station 2 – History; Grey: Station 4 – Communication and ethics), and the five examination stations are shown as dashed lines (Dark Blue: Station 1a – Respiratory; Green: Station 1b – Abdomen; Purple: Station 3a: Cardiovascular; Orange: Station 3b: Neurological; Pale Blue: Station 5: Other). It should be noted that Xcalibre and FACETS calculate their parameters in slightly different ways due to making different assumptions to ensure identifiability, and that the output from the programs is therefore not directly comparable (although there is a mathematical relationship between them). This figure should therefore only be used to give a sense of the relative difference between the stations, rather than to be used to compare specific values of the parameters with those derived by FACETS.