Re: Bias is self-perpetuating in lazy statistics
No. If you read @random's post again you can see that as the incorrect results persist, and the bias gets greater, the numbers get even worse. Even if the situation changes and Group A are carrying fewer knives than Group B their numbers will still be worse because of the self-perpetuating selection bias.
What is required to get meaningful data is that the samples (i.e. those stopped and searched) must be truly random (and also that bias is eliminated in later stages, like deciding whether to caution or prosecute, and at prosecution and trial stages). Otherwise, the data on which the profiling, analysis and AI are based is just complete garbage.