Slide 9 of 14
Notes:
The Bayesian Approach takes the binomial method one step further by including information about prior activities in a source area. For instance, if we knew a large amount of gasoline was released from a storage tank, we would expect the soil concentrations for benzene in that area to be above a target level. We can assign a value for the fraction of soil we expect to be above the target level along with a variance on that fraction. This fraction is identical to the probability I was referring to earlier. For example, in areas where high levels are expected, we can assign a fraction of 0.75 and a variance of 0.25. We can then update the fraction with existing data measurements. We use a beta distribution for this step.
