Quality Score changes by position?

Since CTR decreases by position, does QS?

[chotumotu]

Q1-> Is it safe to assume CTR of a KW is the MOST dominant factor that goes into QS? Approx how important would you say its weight is: 60%? 80%? higher?

Q2 --> So say we use CTR as a proxy for QS. Now CTR of the ad declines as we move down the page...so does that mean QS declines for the same KW as move down the page?
(I would imagine google would somehow index it by position and treat QS to be constant...please let me know)

Thnx!

[AdWordsAdvisor2]

Hi chotumotu,

I can't address how exactly the quality score is derived and what percentage part CTR plays, but I can tell you that we do naturalize CTR by position. Your ad position will not negatively effect your quality score.

AWA2

[chotumotu]

Thank you AWA2.

[JRnow]

while i realize there are many factors involved, i assume CTR is one of the more or most important.