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The Discovery Search Relevance Dashboard leverages user activity log files to analyze submitted queries and how far down the presented results users have to scroll to click on an answer, link or document they deemed most relevant. But engine scoring is a diagnostic and not a prescriptive tool. If the score is low, search engineers still have to determine the problem and introduce changes or software fixes. Regular or continuous monitoring does, however, provide an indication of whether or not the fixes have improved (or degraded) results.
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More detailed information is available on how search relevance scoring works, and how it is used for relevancy tuning and continuous improvements of search results.