Creation of the POP scores
The POP score methodology was developed by Don Levy, PhD at Sienna College Research Institute.

An example of a POP score calculation is as follows:

Goal: Create a summary for a set of 4 items (very unlikely = 0, somewhat unlikely: 1, somewhat likely: 2, very likely: 3), with values of 0-3 each; Approach: 1. Sum the points for all 4 items, total is 0-12 for each person, 2. Sum the totals for all respondents and divide by the maximum total

Details about the RDD surveys
Methodological details for each year of the RDD survey are shown in the table below:

Details about the CBO surveys