One of the most important aspects of an intervention is the people involved. In general, there should be at least three people at an intervention, but no more than 10 [source: Jay]. Most interventions center on the sharing of personal accounts of how the person's behavior has negatively affected friends, family and colleagues. Therefore, it's essential to invite those who have a personal relationship with the person, and who are genuinely concerned for his or her well-being. Not everyone needs to speak or share an individual account, but it's important to have a few people there to talk about their personal experiences. Sharing gives the person concrete examples of why his or her behavior is negative and how it is affecting others.
In many cases, involving children in an intervention is acceptable because they are also affected; however, it's important that everyone involved in the intervention is mature enough to handle the situation with respect and care. Involving children should be on a case-by-case basis and should depend on their ages and maturity levels. If you have concerns about including a child, consider having them write (or dictate) a letter instead of attending in person [source: Finnigan].
Don't include anyone who also participates in the negative behavior or in any way enables it. Most importantly, invite people you trust and whom the person is likely to listen to.