In most circumstances, research participants are pleasant, helpful, and easy to work with. However, there are a few types that can make moderating a session really challenging and put you at risk of not getting the best insights. We only have a short time to gain feedback and insights from participants and certain personas can derail your research study. Based on over 20 years of experience conducting user research, I’ve pulled together a composite of participant characteristics that I’ve encountered into five personas to watch out for and how to effectively work with them.