Not every gathering should be the same size. That might sound obvious, but it's a principle that gets overlooked constantly — especially in strategic planning, where organizations often default to either "invite everyone" or "keep it to the board of directors" without thinking critically about why a particular group size serves a particular purpose.
In her book The Art of Gathering: How We Meet and Why It Matters, facilitator and conflict resolution expert Priya Parker argues that group size isn't just a logistical detail — it's a design choice. And like any design choice, it shapes the experience. The number of people in the room (either in-person or virtual) determines the depth of conversation, the diversity of perspective, the energy in the space, and ultimately, the quality of the outcomes.
Parker identifies what she calls "magic numbers" in group dynamics: 6, 12 to 15, 30, 150, and what she describes as "tides of humanity." Each number carries a distinct quality — a different way that people relate to one another when they gather. And as I've reflected on the process outlined in our strategic planning white paper at Event Garde, I've been struck by how closely our design mirrors her framework — not because we set out to follow it, but because the work itself demands it.
What follows is a look at each of Parker's magic numbers and how they show up across the phases of a well-designed strategic planning engagement. These numbers are tools, not rules — guidelines that help us think intentionally about how many people belong in the room at any given stage of the process, and why.
Groups of 6: Where Intimacy Does the Heavy Lifting
Parker describes groups of six as "wonderfully conducive to intimacy, high levels of sharing, and discussion through storytelling." At this size, every person matters. There's no room to hide, no space for passengers. The trade-off is that you sacrifice diversity of viewpoint — but what you gain is depth, candor, and trust.
This is exactly the energy we want at the very beginning and the very end of a strategic planning engagement.
Our process opens with what we call a virtual kickoff session, and we intentionally keep it small — typically five to seven people, which lands right in Parker's sweet spot. This session brings together a limited number of key staff and board members to lay the groundwork for everything that follows. It's where we discuss why the organization is pursuing strategic planning right now, review key organizational documents, map stakeholders, and craft the strategic planning focus question that will guide the entire process. It's also where we begin to build the trust between the facilitation team and the organization's leaders that will carry us through harder conversations later.
Just as importantly, this small group becomes the first set of champions and ambassadors for the planning process. Because they've been close to the work from the very beginning — shaping the focus question, reviewing the data, understanding the rationale behind the approach — they're equipped to answer questions, build buy-in, and support the process with colleagues who will join in later phases. That kind of ambassadorship doesn't happen in a large group. It happens when people feel genuine ownership, and ownership is built at a scale where every voice shapes the outcome.
Could we do this with more people? Technically, yes. But the work wouldn't be the same. A focus question developed by fifteen people would likely be broader, safer, less specific. The candor required to honestly assess organizational readiness doesn't emerge in a crowd. At six, people tell you what they actually think — not what sounds good in front of a larger audience.
Parker is right that groups this small can't bear much “dead weight” (her words not mine). Every person in this session needs to be there for a reason, and every person needs to contribute. The intimacy isn't a nice-to-have, it's the mechanism that makes the session work.
That same intimacy shows up again at the very end of the process. Approximately 90 days after the focused implementation plan is complete and launched, we schedule a check-in — a one-hour conversation with the executive director, board chair, and essential senior staff or executive committee members. Back to a group of about six. The purpose is simple: check on progress, celebrate successes, name setbacks, discuss course corrections, and identify next steps. It's a focused conversation that brings the engagement full circle.
There's something fitting about bookending a strategic planning process this way — beginning and ending with the same intimate scale, the same depth of conversation, the same level of trust. It mirrors what Parker suggests about the power of six: when the stakes are high and the work is personal, smaller is better.
Groups of 12 to 15: The Problem-Solving Sweet Spot
Parker describes this range as still small enough to build trust and intimacy, but large enough to offer genuine diversity of opinion. It's small enough for a single moderator to manage, yet large enough to generate what she calls "a certain quotient of mystery" — the sense that not everyone in the room knows everything about everyone else, which keeps the conversation dynamic.
In our strategic planning work, this is the size we aim for during focused implementation — the phase where the strategic plan gets translated into specific, measurable action.
After the big-picture work of visioning and strategy development is complete, a smaller working group convenes to build out the implementation details. This group typically includes key staff, board members, initiative leads, and/or other volunteers — people who will actually be responsible for moving the work forward. Together, they explore the current reality for each strategic direction, identify first-year accomplishments, set success indicators, calendar milestones by quarter, and detail implementation steps for the first 90 days.
This is detailed, roll-up-your-sleeves work. It requires people who are close enough to the operations to speak with authority about what's realistic and who are empowered to make commitments on behalf of their teams. Too few people, and you lose critical perspective. Too many, and the conversation becomes unwieldy — people start deferring to the loudest voices or defaulting to vague commitments that no one owns.
Parker's insight about this size being the natural limit for collaborative problem-solving rings true here. At 12 to 15, the group is large enough to represent the breadth of the organization but small enough that every person can contribute meaningfully to the plan. You can still go around the table. You can still hold one conversation. And that matters enormously when the goal is shared ownership of specific, actionable outcomes.
Groups of 30: The Crackle of Possibility
At 30, Parker says that something shifts. The gathering starts to feel like a party — not in the frivolous sense, but in the energetic one. There's a buzz, a crackle, a sense of possibility that smaller groups can't quite generate. The group is generally too large for a single conversation, but with skilled facilitation and the right room setup, it can be managed — and the energy it produces is worth the complexity.
This is the size we work with during two critical phases of strategic planning: the virtual stakeholder orientation and the in-person strategic planning facilitation. In practice, 30 is typically our upper limit for these sessions. Some organizations bring smaller groups — 20 or 25 — and that works well, too. We've found the 20-to-30 range to be our sweet spot: large enough to generate the energy and diversity of perspective the work demands, but not so large that facilitation becomes crowd management.
The virtual stakeholder orientation is a preparatory session for everyone who will participate in the in-person retreat. It covers a lot of ground — introductions, community agreements, a review of key organizational statements and data, an overview of the environmental scan conducted via breakout rooms, and a preview of what's ahead. It's a session that needs to accomplish two things simultaneously: bring everyone up to speed on the substance and begin building the relational foundation the group will need for deeper work. At 30, both things are possible. There's enough diversity in the room to surface multiple perspectives, and enough energy to create genuine anticipation for what's next.
The in-person strategic planning session itself also operates at this scale, and it's where Parker's observation about facilitation skill really matters. Over the course of a full day or more, the group moves through a structured process — developing a practical vision, naming underlying contradictions, and identifying strategic directions. Each of these workshops requires individual brainstorming, small-group work, whole-group conversation, and careful synthesis. At 30, these dynamics become harder to manage — and the question of how to ensure every voice is heard becomes a design problem, not just a facilitation preference.
How do you make a group of 30 work well? Part of the answer lies in the methodology itself. The Technology of Participation (ToP) methods we use are inherently interactive and process-oriented — they move people through individual reflection, small-group dialogue, and whole-group synthesis in ways that create natural entry points for every voice. Part of the answer lies in having a skilled and experienced facilitator who can read the room, manage energy, and make real-time adjustments. Part of it is co-facilitation — having more than one set of eyes and ears in the room to catch what a single facilitator might miss. And part of it is the ecosystem around the facilitation: strong community agreements that the group co-creates and owns, a supportive CEO or board chair who models the kind of participation they want to see, and a shared understanding that the process belongs to everyone in the room, not just the person standing at the front.
And yet, for all the intentionality required, that energy is essential. Strategic planning isn't just an analytical exercise — it's a generative one. The group needs to feel that something meaningful is happening, that the collective is producing something none of them could have produced alone. Parker's description of 30 as the threshold where possibility starts to crackle is exactly right. You want that energy in the room when you're asking people to imagine what their organization could look like in three to five years.
Groups of 150: Trust at Scale
Parker notes that somewhere between 100 and 200 people, a gathering reaches an interesting threshold. Conference organizers she's spoken with consistently describe this range as the tier where intimacy and trust are still palpable at the level of the whole group — just short of the point where the gathering becomes an audience. She connects this to the anthropologist Robin Dunbar's research on the natural size of human social networks: roughly 150 stable relationships is the upper limit of what our brains can manage.
We don't typically convene 150 people in a conference room for strategic planning — but we have done it. In one engagement with a large school of public health at a major research university, we scaled the process to accommodate a significantly larger group, bringing in four facilitators and making substantial modifications to the methodology to ensure the work remained participatory and meaningful at that size. It was a powerful reminder that the process can stretch when the purpose demands it — but it requires intentional design to preserve the qualities that make it work.
More often, though, the spirit of this number shows up in a different way — through the environmental scan, which often takes the form of a member survey.
A well-designed member survey reaches far beyond the people who will ever sit in a planning session. It goes out to the full membership — likely thousands of stakeholders, if not more — and asks them to reflect on the organization's past, present, and future. What milestones have been most significant? What strengths does the organization bring? What challenges or opportunities lie ahead? What benefits do members personally value?
This is where Parker's 150 matters conceptually, even if the actual number is larger. The survey is designed to make every respondent feel that their input matters — that they're part of the organism, not just an audience receiving information. The data that comes back is aggregated into themes and trends that ground the planning group's work in real stakeholder experience, not just leadership assumptions. It honors the organization's history, surfaces what members actually care about, and ensures the planning process doesn't start from scratch or in a vacuum.
Parker would likely note that at this scale, the mechanism of connection changes. You're no longer building intimacy through face-to-face conversation. You're building trust through inclusion — the signal that the organization cares enough to ask and will take what it hears seriously.
Tides of Humanity: The Power of the Whole
Beyond her numbered thresholds, Parker describes one more category: "tides of humanity." Think the World Cup, the Olympics, Times Square on New Year's Eve. These are gatherings where the goal isn't intimacy or even connection in the traditional sense — it's tapping into the collective energy of something much larger than any individual.
We don't orchestrate tides of humanity in strategic planning (though some board meetings might feel that way). But the concept matters because it reminds us what's at stake. The associations we work with don't just serve their members — they often serve entire professions, industries, or fields of practice. A state CPA society setting strategic directions isn't just planning for its membership; it's shaping the future of the accounting profession in that state. A national veterinary association isn't just surveying its members; it's making decisions that ripple out to every practitioner, every clinic, every community they serve. The strategic plans these organizations develop will touch people who will never know the plan exists.
That's why keeping the broader community in mind matters at every stage of the process. When we sit in a room with 30 people developing strategic directions, or work with 12 people building an implementation plan, or start with six people crafting a focus question — we're doing that work on behalf of a much larger whole. The tides of humanity are the professionals, the communities, and the stakeholders whose lives will be shaped by the outcomes. Keeping them in view is what gives strategic planning its weight and its purpose.
Tools, Not Rules
Parker herself acknowledges that her magic numbers are approximations. Every facilitator develops their own list, shaped by experience and context. The value isn't in the specific numbers — it's in the principle behind them: that group size is a deliberate design choice, and getting it right changes everything about the quality of the conversation, the depth of the relationships, and the durability of the outcomes.
In our strategic planning work, we've found that honoring these thresholds — even loosely — produces better results. Small groups for high-trust, high-candor moments. Mid-sized groups for collaborative problem-solving. Larger groups for energy, possibility, and the richness that comes from genuine diversity of perspective. And the broadest reach for inclusion and voice.
The next time you're planning a strategic conversation — or any gathering, for that matter — resist the urge to default to "whoever's available" or "everyone who might want to be there." Instead, ask yourself: What does this moment in the process actually need? What kind of conversation am I trying to create? And how many people does it take to create it well?
The answers might just be magic.
