Question

In each of the following examples, identify the sampling method being used.

1. A sample of 2,000 was sought to estimate the average achievement in science of fifth graders in a city’s public schools. The average fifth grade enrollment in the city’s elementary schools is 100 students. Thus, 20 schools were randomly selected and within each of those schools all fifth graders were tested.

2. A researcher is interested in maximum-security inmates. She groups inmates by the type of crime committed, determines the percentage of the total in each crime category, and uses that percentage to determine the number of inmates randomly selected from each group.

3. A researcher has a population of 100 third grade children from a local school district from which a sample of 25 children is to be selected. Each child’s name is put on a list, and each child is assigned a number from 1 to 100. Then the numbers 1 to 100 are written on separate pieces of paper and shuffled. Finally, the researcher picks 25 slips of paper and the numbers on the paper determine the 25 participants.

Answer 1

*1) Answer is Cluster Sampling

Cluster sampling is a sampling plan used when mutually homogeneous yet internally heterogeneous groupings are evident in a statistical population.

*2)Answer is Multi stage Cluster sampling

Multistage sampling can be a complex form of cluster sampling because it is a type of sampling which involves dividing the population into groups (orclusters).

* 3)Answer is  Simple Random Sample

A simple random sample is a subset of individuals (a sample) chosen from a larger set (a population). Each individual is chosen randomly and entirely by chance, such that each individual has the same probabilityof being chosen at any stage during the sampling process, and each subset of kindividuals has the same probability of being chosen for the sample as any other subset of k individuals