Solid circles show the improvement in performance at each attempt at a) Part 1, b) Part 2 and c) PACES. These are the estimates of the dummy variables in model M2, and show the estimated change in mark (± 2 SEs) from Attempt n-1 to Attempt n, with the abscissa showing n. The horizontal dashed grey line shows zero (no change) and the vertical dashed line shows the horizontal position beyond which the 2 SE confidence interval first includes zero. The dashed red line indicates the expected change for the negative exponential model fitted as model M3. PACES, Practical Assessment of Clinical Examination Skills.
McManus and Ludka BMC Medicine 2012 10:60 doi:10.1186/1741-7015-10-60