The first step in answering this question of “what makes an effective team?” is to ask “what is a team?” More than an existential thought exercise, actually figuring out the memberships, relationships, and responsibilities of individuals all working together is tough but critical to cracking team effectiveness.

The term team can take on a wide array of meanings. Many definitions and frameworks exist, depending on task interdependence, organizational status, and team tenure. At the most fundamental level, the researchers sought to distinguish a “work group” from a “team:”

• Work groups are characterized by the least amount of interdependence. They are based on organizational or managerial hierarchy. Work groups may meet periodically to hear and share information.
• Teams are highly interdependent – they plan work, solve problems, make decisions, and review progress in service of a specific project. Team members need one another to get work done.

Organizational charts only tell part of the story, so the Google research team focused on groups with truly interdependent working relationships, as determined by the teams themselves. The teams studied in Project Aristotle ranged from three to fifty individuals (with a median of nine members).

Once they understood what constituted a team at Google, the researchers had to determine how to quantitatively measure effectiveness. They looked at lines of code written, bugs fixed, customer satisfaction, and more. But Google’s leaders, who had initially pushed for objective effectiveness measures, realized that every suggested measure could be inherently flawed – more lines of code aren’t necessarily a good thing and more bugs fixed means more bugs were initially created.

Instead, the team decided to use a combination of qualitative assessments and quantitative measures. For qualitative assessments, the researchers captured input from three different perspectives – executives, team leads, and team members. While they all were asked to rate teams on similar scales, when asked to explain their ratings, their answers showed that each was focused on different aspects when assessing team effectiveness.

Executives were most concerned with results (e.g., sales numbers or product launches), but team members said that team culture was the most important measure of team effectiveness. Fittingly, the team lead’s concept of effectiveness spanned both the big picture and the individuals’ concerns saying that ownership, vision, and goals were the most important measures.

So the researchers measured team effectiveness in four different ways:

1. Executive evaluation of the team
2. Team leader evaluation of the team
3. Team member evaluation of the team
4. Sales performance against quarterly quota

The qualitative evaluations helped capture a nuanced look at results and culture, but had inherent subjectivity. On the other hand, the quantitative metrics provided concrete team measures, but lacked situational considerations. These four measures in combination, however, allowed researchers to home in on the comprehensive definition of team effectiveness.

Using input from executives across the globe, the research team identified 180 teams to study (115 project teams in engineering and 65 pods in sales) which included a mix of high- and low-performing teams. The study tested how both team composition (e.g., personality traits, sales skills, demographics on the team) and team dynamics (e.g., what it was like to work with teammates) impact team effectiveness. Ideas were pulled from existing research as well as Google’s own experience with what makes an effective team.

They conducted hundreds of double-blind interviews with leaders to get a sense of what they thought drove team effectiveness. The researchers then looked at existing survey data, including over 250 items from the annual employee engagement survey and gDNA, Google’s longitudinal study on work and life, to see what variables might be related to effectiveness. Here are some sample items used in the study that participants were asked to agree or disagree with:

• Group dynamics: I feel safe expressing divergent opinions to the team.
• Skill sets: I am good at navigating roadblocks and barriers.
• Personality traits: I see myself as someone who is a reliable worker (informed by the Big Five personality assessment).
• Emotional intelligence: I am not interested in other people’s problems (informed by the Toronto Empathy Questionnaire).

Demographic variables like tenure, level, and location were also collected.

With all of this data, the team ran statistical models to understand which of the many inputs collected actually impacted team effectiveness. Using over 35 different statistical models on hundreds of variables, they sought to identify factors that:

• impacted multiple outcome metrics, both qualitative and quantitative
• surfaced for different kinds of teams across the organization
• showed consistent, robust statistical significance

The researchers found that what really mattered was less about who is on the team, and more about how the team worked together. In order of importance:

• Psychological safety: Psychological safety refers to an individual’s perception of the consequences of taking an interpersonal risk or a belief that a team is safe for risk taking in the face of being seen as ignorant, incompetent, negative, or disruptive. In a team with high psychological safety, teammates feel safe to take risks around their team members. They feel confident that no one on the team will embarrass or punish anyone else for admitting a mistake, asking a question, or offering a new idea.
• Dependability: On dependable teams, members reliably complete quality work on time (vs the opposite – shirking responsibilities).
• Structure and clarity: An individual’s understanding of job expectations, the process for fulfilling these expectations, and the consequences of one’s performance are important for team effectiveness. Goals can be set at the individual or group level, and must be specific, challenging, and attainable. Google often uses Objectives and Key Results (OKRs) to help set and communicate short and long term goals.
• Meaning: Finding a sense of purpose in either the work itself or the output is important for team effectiveness. The meaning of work is personal and can vary: financial security, supporting family, helping the team succeed, or self-expression for each individual, for example.
• Impact: The results of one’s work, the subjective judgement that your work is making a difference, is important for teams. Seeing that one’s work is contributing to the organization’s goals can help reveal impact.

Organizational behavioural scientist Amy Edmondson of Harvard first introduced the construct of “team psychological safety” and defined it as “a shared belief held by members of a team that the team is safe for interpersonal risk taking.” Taking a risk around your team members may sound simple. But asking a basic question like “what’s the goal of this project?” may make you sound like you’re out of the loop. It might feel easier to continue without getting clarification in order to avoid being perceived as ignorant.

To measure a team’s level of psychological safety, Edmondson asked team members how strongly they agreed or disagreed with these statements:

1. If you make a mistake on this team, it is often held against you.
2. Members of this team are able to bring up problems and tough issues.
3. People on this team sometimes reject others for being different.
4. It is safe to take a risk on this team.
5. It is difficult to ask other members of this team for help.
6. No one on this team would deliberately act in a way that undermines my efforts.
7. Working with members of this team, my unique skills and talents are valued and utilized.

In her TEDx talk, Edmondson offers three simple things individuals can do to foster team psychological safety:

1. Frame the work as a learning problem, not an execution problem.
2. Acknowledge your own fallibility.
3. Model curiosity and ask lots of questions.