Question

Dr. Oishi is an educational psychologist interested in students' attitudes toward math and the effect of those attitudes on performance on standardized tests. He chooses his local school district to study. There are 15 middle schools, and he randomly recruits 250 students. This is an example of which of the following sample techniques?

a. snowball sample
b. systematic sample
c. multistage sample
d. cluster sample

Answer 1

Dr. Oishi is using cluster sampling for his educational psychology study, where he recruits 250 students across 15 middle schools rather than selecting entire schools or ensuring representation across different sub-groups as in stratified sampling.

Step-by-step explanation:

Dr. Oishi is practicing cluster sampling for his study on students' attitudes toward math and their performance on standardized tests. In cluster sampling, all the members of randomly selected groups (or clusters) within a population are studied. Here, Dr. Oishi could have chosen entire schools (clusters) and included all students within those chosen schools. However, he has decided to randomly recruit 250 students across the schools, which might seem like simple random sampling, but given that he is selecting from particular schools within a district, it resembles a cluster sample approach more closely than the other techniques.

Compare the example to other sampling techniques:

• Systematic sampling: A method like this would involve choosing participants at regular intervals from a list, such as every 50th student.
• Stratified sampling: A researcher would use this approach to ensure representation from different sub-groups, for instance selecting a certain number of students from each grade level.
• Multistage sampling: This would involve multiple stages of sampling, possibly including both stratified and cluster methods on different selections.