The Conversation is required only when the first two interventions are unsuccessful in prompting the necessary change in your team member. You see the impact a behavior has on the team, and convincing your team member to take ownership of it is becoming more urgent.
Like the first two steps, the Conversation is not formal–but it does require more time. Plan to spend fifteen to thirty minutes with your team member to pick up the conversation thread established during the Mention and the Conversation and shift the discussion from intentions (“Can you tell me more about why you approached it that way?”) to impact (“Can you tell me what the consequences are when you…?”).
To keep the Conversation from coming off as punitive or intense, remember that you are embodying a coach, rather than a boss. The goal is to show the impact a negative behavior has on the team, because once a person is aware of their impact, they are more likely to make a change.