Click https://www.betterevaluation.org/en/evaluation-options/GoalAttainmentScales link to open resource.
Goal Attainment Scaling (GAS) is an option that can be used as a means of measuring outcome data from different contexts set out on a 5 point scale of -2 to +2. It enables the data to be placed on a quantitative measurement scale thus tackling the problem of how to adequately identify and measure qualitative goal impact and attainment. This is very useful as it enables a linking of measures from the frontline to upper levels of an organization’s management.