Post quality seems to be defined according to the criteria in this main meta post:
Heuristics for detecting a bad answer?
- contains word "help"
- contains word "test" or "testing"
- contains word "thanks", "thx", "cheers", "great"
- contains word "bump"
- contains word "same", "problem"
- contains word "sorry"
- contains word "work", "working"
- contains ":)" or ":-)" or ":(" or ":-("
Character set checks
- contains one or more exclamation points
- contains one or more question marks
- contains all (or mostly) uppercase characters
- contains all lowercase characters
- does not contain any spaces
- does not contain any ascii chars
.., possibly repeated
- includes hyperlink type text (even without the http://)
- includes email address
- content ends in question mark
- answers with low entropy, eg, repeated characters like "asdfasdfasdfjkjkjk"
However, most of the answers satisfying these criteria will probably end up deleted (since that's the whole point of the quality score - to identify potentially delete-worthy answers), and those that aren't will probably already have been edited on their journey through the Low Quality Posts review queue.
If you want to find edit-worthy answers for an Archaeologist badge, a better idea might be to hunt for common misspellings: for example, "Voldermort" in harry-potter posts, or "Jamie" in a-song-of-ice-and-fire and game-of-thrones posts. Searching for these will yield posts which are most likely useful, or at least not bad enough to have been deleted, but which can still be objectively improved by (albeit minor) edits.