Sampling Difference Confusion

Hi there, I'm confused with stratified sampling and cluster sampling. I looked at my textbook and did some research, and I still can't understand the difference.

Would someone care to explain? Thanks.

Edit: Also, if anyone is willing to explain to me sampling and response bias, that would be greatly appreciated :).

Re: Sampling Difference Confusion

Hey Derosion.

Stratified sampling is sampling that is broken into "strata" or disjoint regions of a particular sampling space and samples are drawn from each strata where-as cluster sampling treats every cluster as an individual sampling unit.

Wiki does a nice job of explaining:

Cluster sampling - Wikipedia, the free encyclopedia