ABSTRACT
There are a number of methods, referred to as sample designs. Some of the sample design methods described in this chapter are: simple random sampling, systematic sampling, stratified sampling, quota sampling, cluster sampling, judgemental sampling, and convenience sampling. Quota sampling is very similar to stratified sampling, the only difference is that with quota sampling people do not choose a simple random sample from each strata. Quota sampling is so called because the number of subjects required in each subgroup of the sample is referred to as the quota to be obtained. Random numbers can be found in tables of random digits from booklets of statistical tables or at the back of most introductory textbooks in statistics. Cluster sampling involves splitting the population into sub-groups called clusters. One key problem with cluster sampling is choosing appropriate clusters.
