gives accurate porosity estimates for every shallow invasion of approximately , but can be up to 5 p.u. too low for  invasions. The simple arithmetic average of the estimates, still used by many log analysts, introduces even larger errors.
For every minor infiltration, the tool offers accurate porosity estimates; however, it might be off by up to 5 p.u. for some cases. Employing the simple arithmetic average of these estimates, a practice commonly followed by many log analysts, tends to introduce even larger errors.