Reducing bias in ML model training

Stratified random sampling is a method of sampling that involves the division of a population into smaller sub-groups known as strata. Then simple random sampling with replacement is applied within each stratum. Members in each of these sub-groups should be distinct so that every member of all groups get equal opportunity to be selected using simple probability. This sampling method is also called proportional random sampling. Stratified random sampling is a method of sampling that involves the division of a population into smaller sub-groups known as strata.