Well, as a single sample, I tried the first thing that came to mind in google and duckduckgo. "breast shimming" which refers to the process of adjusting the magnetic field of a MRI scanner to obtain images of the breast (relevant to a project I'm working on). Every single duckduckgo result is irrelevant. Most of googles results are relevant. It's too bad because google is somewhat hit or miss for me. Someone needs to…
Did you turn safe search off on DDG? When I gave these queries a go, I noticed that DDG stripped "breast" out of the query. The results seemed much more relevant once safe search was disabled. Not that I'd want to go around with safe search disabled all the time...
Edit: FWIW, I fixed this: http://duckduckgo.com/?q=breast+shimming should now work as well.