Effect of teaching on total data interpretation scores for each teaching format. Data were expressed as percentages of the maximum possible score before and after teaching and are illustrated as medians bisecting the 25 and 75% percentiles and the limits of the range. There were no differences in performance between groups prior to teaching. All groups showed a significant improvement. Analysis by general linear model with repeated measures showed a significant improvement in performance after teaching (*: P < 0.001 in all cases).