What are open response questions? What are closed response questions?

Open response questions are questions that have more than one correct answer or more than one acceptable way of arriving at a correct answer. Closed reponses are limited: yes or no, multiple choice etc...

It actually is a reasonable response to SOME (and I do mean SOME) questions. Sometimes, people plead for "open-mindedness" as a euphemism for acceptance. In these people's minds, someone is only "open-minded" if that person agrees with everything they say and never asks any questions or raises any objections. Being open-minded entails giving a proposition due consideration, but it doesn't entail indiscriminate acceptance of everything one is told. When someone calls for "open-mindedness" and means "unquestioning agreement with everything I say," they are essentially asking others to be so open-minded that their brains would fall out. Granted, some close-minded people just use it as a knee-jerk response to anything they don't even want to think about. They figured it sounded clever so they picked it up and used it without understanding its meaning. The expression was originally meant to highlight the difference between skeptical consideration (true open-mindedness) and total credulity (brain falling out). But unfortunately, some close-minded people use it as a reflexive rejection of open-mindedness altogether.