The feature rating system described (1 = Completely dissatisfied, 2 = Somewhat dissatisfied, 3 = Neither satisfied nor dissatisfied, 4 = Somewhat satisfied, 5 = Completely satisfied) is based on an ordinal measurement scale. Ordinal scales categorize data into distinct groups that have a meaningful order or ranking, but the intervals between the ranks are not necessarily equal. In this case, the ratings provide a rank order of satisfaction levels.