Maybe a combination of numbers: one of them is a measure of satisfaction with answer by OP, others are measures by mentors of : originality, quality, opening up new avenues, good example. Say from 0-5. Then we can average the measures given by all mentors and select those with, say, score from 4-5 as the good ones and those in 0-1 as the worse ones and look for patterns, for qualities . Maybe we can also link to these from the main page to illustrate what we consider to be quality posts. These types of analyses are done at corporate level under the general term " metrics" with, e.g., measures of product satisfaction.