Beginning the week of September 12, new keywords and keywords that haven’t received any recent clicks and impressions will have a reported Quality Score in AdWords of null, represented by dashes (“–“).
By default, any keywords with null Quality Scores will be excluded from reports and automated rules that have Quality Score filters unless you check a new box that will appear with this change to include them. Google recommends reviewing any reports, filters, rules and scripts that include Quality Score before September 12 to be sure they will function properly.
This change is an update from July 2015, when Google decided to assign new keywords a default reported Quality Score of 6. At the time, Google said assigning a single default Quality Score for new keywords would “simplify some of our core systems.” The default Quality Score updates after new keywords receive sufficient impression data.
Before that shift, Google used to assign a new keyword a Quality Score that was calculated based on the keyword’s performance across the entire system and the individual account’s historical performance.
The switch from a default reported score of 6 to null won’t affect the ad auction or the way ads are served. For users, null is a clearer placeholder for reported Quality Score than a default of 6.