Capitalizing keywords raises the QS
I have capitalize all first letter of all my group's keywords list. Doing that I noticed that my Quality Score increased right the way. My question is,#1. is Google thinking that all my keywords are Nouns? (or does it matter?)
#2. If my searchers enter the keyword with low case is it going to trigger my ad?
Re: Capitalizing keywords raises the QS
Most likely the increase in QS is only temporary. AdWords is recognizing the keyword as a new keyword. When new keywords are added, the performance of that keyword across all advertisers is used when calculating the QS. After a certain number of impressions (1000 or more), you own performance of the keyword becomes the important factor.
The lower QS on the un-capitalized keyword indicates that you are getting lower than average for all advertisers CTR for that keyword. Chances are, the QS on the capitalized keyword will go down to meet that when it was not capitalized.
Google ignores case when matching up keywords to the search query. The only time capitalization really comes into play is with DKI, in which case AdWords will show the keyword as is in the ad.
I'm sorry to tell you that you have not found a secret method of increasing your QS. At best, it is only temporary. The rest depends on you, how well your ad copy matches up to your keywords and the CTR for those keywords will determine "relevancy" and your future QS.
Best of Luck!