A good interview should be planned using a mix of different question types. They should always be tailored towards the specific qualities you'd like a candidate to demonstrate relevant to a particular role. These questions should give you insight into their strengths, weaknesses and how well they will fit into the team. Here is a selection of the main types of questions to ask when interviewing
The standard competency question
These are the most common type of questions to ask when interviewing, and will usually begin with the phrase along the lines of "can you give me an example of when you…". They can be tailored to suit whichever skills you'd like the candidate to tell you about, for example, delivering excellent customer service, resolving a conflict or influencing a senior stakeholder.
Competency style questions are good for when you want to find out about specific competencies or skills the candidate has, and how they have used them to resolve previous situations. Good candidates will often plan responses to these, and should give clear, thought-through examples.
Look for evidence in their answers that they can give you a clear situation, the task at hand, the action they personally took, and the (positive) result of that action - the STAR method.
The follow-up question
Follow-up questions allow you to get more detail, and look beyond the glossy prepared answer, which, although sounding impressive, may cover up a lack of detail or personal involvement. Asking good follow-up questions allows the candidate to engage on a higher level, and have to think on the spot a bit more, as they might not be as prepared for one of these.
The curveball question
If you really want to test a candidate's ability to think on their feet, throw in a curve-ball or two. These can be completely unrelated to the job, but may be an extension of something on their CV or relate to current affairs that you'd like them to comment on or explain to you. It will test their decision-making under pressure, and the ability to articulate an unprepared response, which can be very important in some jobs.
The hypothetical situation question
Some love and some hate these, but they can be seen as a very good example of testing rational thought and logical reasoning quite quickly. Such questions are normally along the lines of asking the candidate to imagine they are in a certain situation, and then asking them to make a decision, based on information and parameters provided.
The "describe yourself" question
These can come in many guises, and you can ask candidates to imagine what their previous boss or co-workers would say about them, or just to sum themselves up in a few words. This will show whether a candidate can empathise with another person's point of view and express it, or their ability to give a succinct answer when only a few words are required.