A colleague can certainly be a good reference, at least as good as a boss. But it’s important to clarify what type of working relationship the reference person has/has had with the candidate so that the questions can be adapted.
If it is about a candidate who is reasonably new to working life, it is also fine to take a football coach, a teacher, etc. – someone who can give examples and answers to work-like or motivational situations where the qualities sought may have been applied.
A reference should be kept short and concise, do not drag on too much. Therefore, it is good to write a clear template with which questions to ask.
When should you contact references?
As we mentioned above, references are generally contacted as a last step in a recruitment process.
It’s good to give those who are to be references some time to prepare, so feel free to schedule a time when the conversation is to take place so that they can sit apart and have time to think through their answers before the reference questions are asked.
If the candidates have little or no work experience, it can be good to take references earlier in a recruitment process, e.g. during a mass recruitment for the grocery store. There, perhaps personal characteristics weigh more heavily than specific experience. So it’s always good to let candidates know when you’re going to take references in a recruitment process, whether it’s early or late, so the candidate knows when they’ll need to provide their references.