Ask about past work
To assess collaboration, ask: “Tell me how you reached a decision when two departments had different priorities.” Ask what the person did, which options they considered, and what happened.
Ask about a work scenario
Give everyone the same scenario. A delivery is late, the customer needs an answer today, and two teams are offering different dates. Ask what the person would do first and why.
Define the scale in advance
Write down what each level looks like. At one level, the person names the parties. At the next, they identify constraints and agree on a next step. Where several interviewers are involved, ask them to score answers independently first.