The food isn't fancy, but it's certainly an 'improvement over' what we're served at school.
His cooking needs 'improvement'. = There's still 'room for improvement' in his cooking.
The editor made some 'improvements' to/in the article before it was printed.
(..) I would never use a transporter. The original Sheldon would have to be disintegrated... ...in order to create a new Sheldon. Would the new Sheldon be in any way an improvement on the old Sheldon? No, he would be exactly the same. That is a problem. So you see it too? Dr. Hofstadter, Dr. Cooper. (..)2008 TvShow: The Big Bang Theory Title: The Jerusalem Duality Season: 1 Episode 12