# Establishing prior mode: Histogram of belief

A prior mode can also be calculated by undertaking a histogram of belief with the survey team. This is done by asking each of the survey team to write, on a post-it note, what they believe the prior mode is and then adding it to a flipchart. Once all post-it notes have been added, the survey leader should then arrange them from lowest to highest and take the median of all of the estimations. This figure should be taken as the prior mode of the histogram of belief. NB: The prior mode of the histogram of belief can be added to this template in order to define the average prior mode.