function calibration_check(predicted_probs, actual_outcomes, bins=10):

   for bin in group_into_bins(predicted_probs, bins):
      average_predicted = mean(bin.predicted_probs)
      actual_rate = mean(bin.actual_outcomes)
      report(average_predicted, actual_rate)
 # well-calibrated: among cases predicted 70% likely, about 70% actually happen
