When movements are very small - that is, they are five generations or smaller in size - they can be fairly easy to count. You can even track the generations on a big piece of paper or a computer spreadsheet.
A simplistic diagram might look like:
Now, in reality, if I saw a movement that diagrammed out like this, I'd be suspicious - it's "too perfect." Movements are messy, and are very rarely (and only randomly) exactly like this. But this illustrates the point: a set of churches can be diagrammed on a page. Globally, the average is about 15 to 18 per group; so we could round to 20 and say this diagram represents between 250 and 300 people.
We can know a lot about this group: the names of the leaders of the groups, the locations of the groups, when they meet, and so on. It's not likely we'd know all the people in the group--once you get past 150, it's not easy to hold that kind of information in one's head--but it is possible to track this on a regular basis.
This kind of graph can also be the 'nucleus' of a larger movement: that is, movements are made up of smaller "4 generation" collections. We can track these "families" within larger extended families; any single individual within the "family" can easily describe his family using five relationships:
These are "spiritual" relationships (which is why I only identify one parent and grandparent--although obviously your "spiritual parents" might be a couple etc). The point here is that you can articulate who mentors you, and who mentors them - and you can articulate who you mentor and who they mentor. Doing so places you in a "five" generation stream, and brings all of the generations into view. (Some of these relationships will obviously parallel "demographic" or "birth" relationships; some will be purely spiritual.)
This is one easy way to begin "counting" within a movement. It also brings in an element of "self-assessment": Anyone who looks "up" and "down" in a demographic family would be able to know where the spiritually mature and spiritually immature are. The same can be said in a spiritual family. And, it begins to introduce the idea of leaving a legacy and generations that are outside your view: great-grandparents won't always know all of the great-grandchildren; we have to leave the future to God.
For most movements, this form of "counting" would be enough - many movements are within the scope of this size. In the next post, I'll look at how we can begin to count tomato plants, bushes and Redwood forests.