...before you actually interview them. You interview candidates and then compare them by their strengths and weaknesses. Sometimes you have a clear idea before hand of what you want to find but many times you think you know what you want before you start the interview process and then you get a candidate who just blows you away in the interview with unexpected stuff you didn’t even anticipate and earns the job.
There’s nothing wrong with having an open mind going into an interview process and letting someone wow you with the passion or vision they would bring to the job.