science of social blog

Last week, I discussed the Lorenz curve and how to use it to quantify precisely how much content is contributed by various portions of the community population. So, one of the concepts I discussed last week was the utility of the Lorenz curve with data from Lithosphere.

The question is what does the Lorenz curve for other communities look like?

In last week's post, I presented summary data on what is often referred to as the 90-9-1 rule. Although participation inequality is not news in itself, we have found that the extent of this inequality is not uniform across communities. Honestly, the only rule that 90-9-1 represents is a rule of thumb--definitely not something that should be taken literally.

90-9-1 is really just a packaged way of saying:

• The majority of the users in a community are lurkers
• Among the contributors, there is a small fraction of hyper-contributors that produce disproportionately large amounts of content

But exactly how big is that "majority", what percentage of the users are hyper-contributors, and precisely how much content do they actually generate?

If you've ever managed a community you've probably heard of the "90-9-1 rule". If you have observed a community closely, you have probably seen it in action.

Soon after a community launches, users begin to participate, but each user participates at a different rate. The minute difference in participation levels is accentuated over time, leading to a small number of hyper-contributors in the community who produce most of the community content.

But how real is this rule? Do all communities follow this rule consistently? If not, how far off is the deviation? Is the proportion really 90:9:1, or is it more like 70:25:5, or 80:19.99:0.01? Let's find out...