You can use this process when you need information from someone who is not a party to the proceeding and you cannot get this information any other way. This would also apply when the witness will not respond to your letters or telephone calls, so you need to compel him or her to answer your questions.
You must conduct an examination for discovery, not a deposition, if a person is a party to the proceeding.
If a person refuses to answer your questions, you must apply in chambers to get the court to order the person to attend at an examination. If you get an order from the court to examine the witness, you will need to prepare and serve a subpoena in Form F23.
This procedure is rarely used. If you think it is going to be necessary in your case, you may want to consult a lawyer. They can let you know if there might be another way to get the information, as well as give you a sense of your chance of success.