Optimal size groups

Hi everyone,

Theoretical question for you. What have you found to be an optimal size group for engagement in your communities?

For example… Our in-app community has ‘open groups’ about certain topics (created by the org), which members can join as soon as download the app community. After they make friends, their friends can invite them to ‘private groups’ which are member-created groups about whatever they want.

These private groups generally see higher engagement than the open groups do. Do smaller groups always have higher engagement? What’s the optimal size community? And do you need both big and small groups?

There’s now some discussion around removing the ‘open groups’ to base the community solely on these smaller ‘private groups’ as engagement there is higher, and but I think we need interactions based on both one to few and one to many.

Curious to hear what others have to say?

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This is literally the same exact phenomena that Facebook is discovering between their main network versus Facebook Groups. The groups tend to have higher forms of engagement, which is why Facebook is going full-speed ahead at making Groups a core part of their features.

As the community advocate for Invision Community, I’ve talked to the community admins of some truly fantastic and wonderful communities … like a Santa Claus community, or a Nano-Reef community (literally small tablestand aquariums), or a German Typography forum, or an LGBT teen support center, and their communities number anywhere from thousands to tens of thousands yet they’re super passionate since they’re very niche topics within the world.


Well, I’m not adding any advice, but I have similar questions about community sizes.

More specifically for this subject; My community is a private community as we are a subscription based site. We don’t have as many people participating as I would like, so when we tried to open a few sub-groups for specific types of artists… I guess we didn’t have enough members to make this possible. We had people join but nearly no one participated once in.

We kept them going, I really can’t remember for how long, they had mods and they were posting and trying to be productive but after a while we decided to put the idea in our back pocket for later.

Is there an optimal size for a community to warrant subgroups?

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Thanks @joelr - yes indeed, Facebook seems to be grappling with the same phenomenon. And agree with your that the more niche, the higher engagement (once the right people join!)

@michaelakatrina at least people joining demonstrates the groups were of interest. Sounds like your typical issues with critical mass.

@richard_millington any thoughts on optimal sizes for subgroups?

Hey, sorry I’m up against it at the moment on a few projects.

There’s a short and long answer to this .

It depends on a lot, I’d read this: http://www.lifewithalacrity.com/2008/09/group-threshold.html which I think is the best primer on the topic.

If you want a small, close, group of peers - it’s probably 5 to 10. If you want mid-sized groups to facilitate high levels of knowledge exchange, it’s probably around 50 to 150.

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Interesting read, thanks @richard_millington.

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