In order to measure customer sentiment among mall loyalty members with regard tomall promotional programs, Steven the stats intern was assigned to collect some data. He used demographic data to collect contact information on female and male patrons in various demographic (racial/ethnic/nationality) groups in various percentages, but not equally so. (A senior manager later told Steven to disregard this approach since it has historically been deemed inferior or insufficient.) Which statistical sampling technique best describes his methodology?

1. cluster sampling
2. convenience sampling
3. judgment sampling
4. network sampling
5. quota sampling
6. simple random sample
7. snowball sampling
8. stratified sampling
9. systematic sampling