Final answer:
Professor Kirstin is using integrative problem-solving as the method for conflict resolution, which brings all parties together to find a collectively acceptable solution through a majority vote.
Step-by-step explanation:
The conflict resolution method being employed by Professor Kirstin is integrative problem-solving. By setting a department-wide meeting to resolve the conflict through a majority vote, the approach aligns with integrative problem-solving where the interest of all parties is considered, and they work collaboratively to find a solution acceptable to all. It is not just a compromise as it involves the whole department, not just a balance between two parties; it is not forcing or dominance and suppression since it involves a vote rather than a decision imposed by one individual.