You are on the interview. You ask. You make notes. Knows what critical path is. Plus. Has the idea how to organize a small project. Plus. Gantt charts have eaten him from the hand. Plus. Yawn. Risk management isn’t one of strengths. Minus. Would deal nicely with tough situations in projects. Plus. Etc.
Is that all? No. So far you know nothing about character of the person and how he will interact with the rest of the team. Sure you will ask about three strengths and three weaknesses but it won’t really tell you much. How the get the knowledge then? Have some soft questions which allow candidate to talk more not necessarily focusing about merits. Then read between lines.
If you ask about the most interesting project and you hear about another simple database application it tells you something about creativity. When you ask how the candidate deals with issues he can’t resolve by himself only the first idea is to go ask the boss you can imagine how self-reliant the guy is. The less obvious questions you have the more you are able to find in answers. Between lines.
Whole avoiding hiring mistakes series.