Questioning Techniques
Open and Closed QuestionsA closed question usually receives a single word or very short, factual answer. For example, "Are you thirsty?" The answer is "Yes" or "No"; "Where do you live?" The answer is generally the name of your town or your address.
Open questions elicit longer answers. They usually begin with what, why, how. An open question asks the respondent for his or her knowledge, opinion or feelings. "Tell me" and "describe" can also be used in the same way as open questions. Here are some examples:
What happened at the meeting?
Why did he react that way?
How was the party?
Tell me what happened next.
Describe the circumstances in more detail.
Open questions are good for:
Developing an open conversation: "What did you get up to on vacation?"
Finding out more detail: "What else do we need to do to make this a success?"
Finding out the other person's opinion or issues: "What do you think about those changes?"
Closed questions are good for:
Testing your understanding, or the other person's: "So, if I get this qualification, I will get a raise?"
Concluding a discussion or making a decision: "Now we know the facts, are we all agreed this is the right course of action?"
Frame setting: "Are you happy with the service from your bank?"
Source: https://www.mindtools.com/pages/article/newTMC_88.htm