This is incredibly good advice. All MTurk tasks of a small size or that will be approved by a single person, should ask an open ended question, that requires a

This is incredibly good advice. All MTurk tasks of a small size or that will be approved by a single person, should ask an open ended question, that requires a response. This greatly reduces fraud, and shoddy work. And it has a tendency to highlight the really good workers (some of which are amazing!) - maximizing your benefit as a requester.