As part of a facilitation peer learning group the below probing questions and communication guides were past around. It's a good summary to help an agile coach drive 'smarter thinking' among the team. Recently a facilitation peer learning group shared a list of 'probing questions' and 'communication guides to help provide effective facilitation. As a coach it's good to have a variety of language techniques up your sleeve and below are a few that may help...

 
Probing Questions:
When seeking more detail, there are a number of types probes you can use, depending on what they are saying and what you want to discover.
Clarification.
When they use vague or unclear language, or when you just need more detail, seek to further understand them by asking for clarification.

• What exactly did you mean by 'XXX'?

• What, specifically, will you do next week?

• Could you tell me more about YY?

 
Purpose.
Sometimes they say things where the purpose of why they said it is not clear. Ask them to justify their statement or dig for underlying causes.

• Why did you say that?

• What were you thinking about when you said XX?

Relevance.
If they seem to be going off-topic, you can check whether what they are saying is relevant or salient to the main purpose of inquiry.

• Is that relevant to the main question?

• How is what you are saying related to what I asked?

Completeness and accuracy.

You can check that they are giving you a full and accurate account by probing for more detail and checking against other information you have. Sometimes people make genuine errors (and sometimes deliberate), which you may want to check.

• Is that all? Is there anything you have missed out?

• How do you know that is true?

• How does that compare with what you said before?

Repetition.

One of the most effective ways of getting more detail is simply by asking the same question again. You can use the same words or you can rephrase the question (perhaps they did not fully understand it first time).

• Where did you go?

• ...

• What places did you visit?

You can also repeat what they have said ('echo question'), perhaps with emphasis on the area where you want more detail.

• He asked you to marry him??

Examples.
When they talk about something vaguely, you may ask for specific examples. This is particularly useful in interviews, where you want to test both their truthfulness and the depth behind what they are claiming.

• Sorry, I don't understand. Could you help by giving an example?

• Could you give me an example of when you did XXX?

• Tell me about a time when you ___.

Extension.

When they have not given you enough information about something, ask them to tell you more.

• Could you tell me more about that, please?

• And what happened after that?

• Then...

Evaluation.
To discover both how judgmental they are and how they evaluate, use question that seek evaluation:

• How good would you say it is?

• How do you know it is worthless?

• What are the pros and cons of this situation?