happiness is hard to measure, but I can easily think of metrics that indicate unhappiness off the top of my head. not clicking through any of the hits, continui

happiness is hard to measure, but I can easily think of metrics that indicate unhappiness off the top of my head. not clicking through any of the hits, continuing to the second page of results, and retrying the same query phrased differently are all strong signals that the user was not satisfied with the results.