The description of this groupImprovementNotation extension says "Indicates how the calculation is performed for the group, including proportion, ratio, continuous-variable, and cohort. The value set is extensible, allowing additional group scoring types to be represented.", which is incorrect. 

It should be updated to something like "Indicates whether improvement in the measure group is noted by an increase or decrease in the measure score."

Another issue:

In both DEQM individual and summary MeasureReport profiles, the short description for the groupImprovementNotation element and the scoring element just shows "Extension". It should add a meaningful short description instead for both.