(This actually changes the way we should test)
This Overlooked Variable Is the Key to the Pandemic.
It’s not R.
The definition of k is a mouthful, but it’s simply a way of asking whether a virus spreads in a steady manner or in big bursts, whereby one person infects many, all at once. After nine months of collecting epidemiological data, we know that this is an overdispersed pathogen, meaning that it tends to spread in clusters
By Zeynep Tufekci
https://www.theatlantic.com/health/archive/2020/09/k-overlooked-variable-driving-pandemic/616548/