I noticed that I have some keywords in my AdWords that are totally applicable to my site but the quality score of the keyword is 4 or 5. I'd like to get it up higher by creating custom versions of my site's home page (landing page) targeted specifically for people searching on those keywords.

So for example, if we pretend my site sells pet food, my current home page has the phrase "dog food." I have a specific AdWords campaign for people searching on cat food (with cat food-specific ads). I'm thinking about changing the URL on those ads to something like http://mysite.com/cat.html, so a different home page comes up with the phrase "cat food." My thinking is that will help Google see that this new landing page is appropriate for the keywords and will raise my quality score for the "cat food" keywords.

(Note that none of what I'm doing is shady or misleading; nobody would disagree that all of the keywords and ads I've created are perfect and appropriate for what my site offers.)

Question: is what I describe the correct way to raise poor quality scores on keywords, and will it help?