Can't be "accurately" correlated because the subjective part is the flaw here. That's what the OP has proposed to eliminate with his DOE.

No, the real problem, should anyone do this, is the meltdown on BF as everyone desperately and angrily fights to hold on to their subjective notions...and eventually convince themselves that no matter what the data says, their subjectivity is actually more accurate.

Then one would have to tackle the marketers...and the ridiculous James Huang of Cyclingplus.

It might be less work to not do this, and just let people believe whatever they want.