According to the Enneagram, a Type Three is sometimes known as The Achiever. Motivated by a desire to feel valuable and worthwhile, The Achiever can appear to be a charmer or a professional, depending on their wings (another element of the Enneagram). At times, the Three can become overly concerned with their appearance to others, and this can show up as workaholicism and competitiveness in their teams.
In a PLC, the Achiever may be the one to excite the team about success experienced through the process. The Achiever finds fulfillment out of appearing successful, so if results are strong in the data, this teammate may feel really good.
Type Three's worst case scenario would be a team that is complacent and content with doing what they've always done. A Three hates the idea of "good enough" in terms of student achievement, and they really can't stand it when people put limits on learning for students. They may or may not tell you, but if their students perform the best--they are okay with that!
For a Type Three to thrive, there does need to be a consistent focus on data and results. Additionally, Threes may need the norm that it's good for the team to strive for continuous growth. At times, a Three may need to hear public praise (at least within the team) to acknowledge the impact they have on the process.
Provide ample time to explore, analyze, and celebrate results for the Three. Encourage the Three to ask, "What else can we do" and also provide them with a boundary to return to previously successful strategies (rather than always seeking something new and innovative). Just because an idea may appear to be impactful does not in fact mean it will be.
A Type Three, at their best, is confident, goal-oriented, productive, playful and decisive. They want their students to take pride in their work and find success. They also care about the success and impact of their overall school on the community in which they serve. When their fear of worthlessness subsides, they are able to celebrate the teams' successes over their own, and that's a great feeling.