Fig. 1From: Estimating the number of usability problems affecting medical devices: modelling the discovery matrixBias in the prediction of m: the mean error and 95% fluctuation interval (as a percentage of the true m) as a function of the sample size (n). The results are presented for various probabilities of problem detection ((μ, σ), columns) and various numbers of usability problems (m, rows). The dashed line represents the true mBack to article page