Optimal Scale (or "Size Matters")


Different sizes of groups behave differently. Choose activities and processes that are appropriate to the group size, or size sub-groups so that they match the activity.


This pattern emphasizes the importance of selecting activities and processes that are appropriate for different sizes of groups, work teams, or even the seemingly minor differences of working in pairs or triads. Careful deliberation and choices based on group size can improve the effectiveness and efficiency of these groups. Alternatively, subdividing the group into subgroups that are the appropriate size for the activity can also be effective.

In general, smaller groups can foster intimacy and strong relationships but are limited in the diversity of perspectives or resources. On the other hand, larger groups will have greater resources and likely have more diverse skills and perspectives at the cost of more time and effort to maintain relationships and group dynamics.


Even small differences in group size can make a significant impact. For example, group work in trios are more accountable than pairs. Work teams or "squads" of around 5-7 offer some of the benefits of both small and large groups — the ability to function effectively while still having the intimacy and intuitive collaboration of the smaller group.

Be aware of "nadir" group sizes, such as around 12, which can be dysfunctional when using small group processing, and groups larger than 90, which require special consideration.

From the pattern mailing list, Christopher Allen wrote:

"You might be able to say that Optimal Scale is sufficiently covered by "Subgroup and Whole Group" or "Mode Choice", or "Right Size Bite", which is probably why it isn't in the current list. But it is *VERY* important for online groups because our scale can range so much more widely. Thus it may deserve to be included in a 2.0 list."

From the pattern mailing list, Dave Pollard wrote:

"I think Subgroup and Whole Group is as close as we get, Christopher. Your writings on this subject are legendary (I knew you in this context long before I got involved with GPLP). When we developed GW, we kind of acknowledged, I think, that the size and membership of the group are usually not within our control, so adapting to the reality with Subgroup and Whole Group, Embrace Dissonance and Difference, Holding Space, History and Context etc. is often the best we can do. History and Context is about knowing who's in the group, what their styles and issues are, and anticipating what will happen when they meet, both in design decisions and improvisationally.

"Beyond the issue of how group size affects how we facilitate is the larger issue of group makeup in general. What do we do if important knowledge or ideas or viewpoints aren't represented? When the power dynamics are dysfunctional? When the group lacks essential capacities needed for any effective group work? When only half the people who were supposed to show up show up? We talk it out, name it, suggest possibilities, get consensus on how to deal with it. I think deciding how to manage different group sizes is part of that deliberation -- there are no set rules (I've been in groups of 12 that work together brilliantly without intervention, and many more that cannot accomplish anything without being broken up and heavily facilitated). The facilitator's job of Holding Space is a combination of planning and playing it by ear to deal with a variety of possible issues of group effectiveness, of which group size is just one (although obviously an important one).

Christopher Allen wrote:

"Dyads are good for emotions, triads for efficiency, small even number groups need more time to deliberate (which may be good or bad), small odd sized group deliberate faster (which may be good or bad), 5-7 is a good size for small group processes, 11-13 a rough size, at 20 new natural group processes emerge but require a different kind of facilitation skill. 80-90 things start getting tough again, really tough at 150. >150 are you sure it is group?"

Someone wrote:

"I'm still not convinced though that what you propose is a pattern.

To try a diffferent example, what about the common wisdom not to do certain kinds of things right after lunch because folks will fall asleep or at least be lathargic and unfocused. Important if designing an all day event to know what works best, what to avoid and all, in this regard, but is it a pattern about "consider energy levels" or merely good practice in a specific kind of circumstance? "


* Dyads & Triads — The Smallest Teams (by Christopher Allen in Life With Alacrity Blog 2013-04) - http://www.lifewithalacrity.com/2013/04/dyads-triads-the-smallest-teams....

* Community by the Numbers, Part One: Group Thresholds (by Christopher Allen in Life With Alacrity Blog 2008-09) - http://www.lifewithalacrity.com/2008/09/group-threshold.html

* The Dunbar Number as a Limit to Group Sizes (by Christopher Allen in Life With Alacrity Blog 2004-03) -http://www.lifewithalacrity.com/2004/03/the_dunbar_numb.html


Image: Trust Spiral, from Life With Alacrity Blog - Community by the Numbers, by Nancy Margolis


John's picture

Right Size Bite is about choosing "chunks that are an appropriate match for the time and people you have"

Christopher's heart description above includes matching chunks to people, and the reverse - sizing the number of people as appropriate to the activity you have. Time is not in the heart or full description, and it seems to be a third related dimension. So how about something like this as a heart:

Find balance among the number of people in an event or subgroup, the duration - possibly including more than one time together, and the chunk of learning, work, process, etc. the group is to address.

I still like "Right Size Bite" as a name for this pattern. I suppose something like Balance Number, Time, and Activity communicates the three-part nature of the heart better, but in this instance I prefer the poetic title we have. Our hearts are short with the idea that people will actually read them (and more than once). It is definitely a balance card though, we have a bunch, at least two starting with that word.

Duration would be expanded on in the full description to include the inquiry of how many times to meet if that makes sense (see Iteration), how long to meet each time - both planned in advance if there is that opportunity/preference, and allowing it to emerge and respond to other factors on the fly. Also, how much time is left between each in whatever series of sub-times. Whole Group and Subgroup often applies again to this aspect of the pattern. (Think of 'meetings' that happen with butterflies, and/or breaking bread, among roommates in multi-day events, etc.)

Also related is Seasoned Timing, which is about the right moment for something, not durations.

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