Fig. 4. Signal averaging reveals a reliable clinical performance score from a noisy background. The first 100 sequential Zrelscores are shown for a single resident (blue circles ). The running average and the upper and lower 95% CIs on the running average are shown by the red filled circles and red lines , respectively (A ). Z-scores are distributed broadly about the mean. Z-scores (N = 100) from the same resident are displayed as a histogram with a bin width of 0.25 (B ).