Finds of stone artifacts have been catagorized
into four groups at Koobi Fora:
| 1. Occurrence type A: concentrations of artifacts with little or no associated bone. |
| 2. Occurrence type B: modest numbers of artifacts associated with bones from the carcass of a single large animal. |
| 3. Occurrence type C: a concentration of artifacts with an obvious area of broken bones from the carcasses of several different animals, usually from different species. |
| 4. Occurrence type D: artifacts dispersed at very low density over an ancient landscape or within a sediment bed. |
