Sample Design A school board at a local community college is c...

Question

Sample Design A school board at a local community college is considering raising the student services fees. The board wants to obtain the opinion of the student body before proceeding. Design a sampling method to obtain the individuals in the sample. Be sure to support your choice.

Accepted Answer

Hello everybody, glad to have you back. The next question says, a state college plans to change its campus shuttle routes and wants to estimate the proportion of students who would use an expanded evening service. Which sampling design is most appropriate to ensure representation from the different campuses and enrollment types and why? A simple random sampling of all enrolled students because it is always the most efficient and unbiased method. Cluster sampling by randomly selecting a few class sections and surveying all students in them because classes naturally group students by schedule. See stratified random sampling with strata by campus and enrollment type because it ensures representation from each subgroup and reduces variants. Or convenient sampling by surveying students at the main library entrance because it is fast and captures many shuttle users. So note that our question specifically tells us that they want the sampling design to ensure representation from the different campuses and enrollment types. So, if we want to make sure that specific subgroups are accurately represented within the whole, What we would look at is what's called stratified random sampling, and we see that term in choice C. Which means that we first subdivide our population into groups with a shared characteristic. Then once you've subdivided, and in this case, you could divide by campuses, enrollment types, then you make a random selection from each group. And this ensures the best representation of each of these different groups, uh, especially when it comes to small populations, where if you did a random sample of the whole entire population, You might not ensure that, for instance, a very uh small campus or a less common enrollment type is represented. So that's why choice A is incorrect, because this doesn't ensure um representation from these different campuses and types. Then choice be cluster sampling by randomly selecting a few class sections and surveying all the students in them. This again, doesn't make sense in this context, because if we're just going by class time, we might be underrepresenting um certain enrollment types. In addition, if they want representation from the different campuses, presumably you'd have to be careful. That the different campuses were represented equally among the different class, the class sections you picked. So again, not. Properly representative as defined by the conditions we're asked about. And then finally trustee convenience sampling because it is fast and captures many shuttle users again. This would not be properly representative. There might be something about people who are at the main library entrance. They might be less likely to be, maybe there's a library on another campus, uh, that students from that campus are more likely to go to than the main library. Again, maybe by enrollment type, students are less likely to be at the library, so not representative by the criteria we're given. With convenience sampling, we always risk selection bias. There's something about that group at the main library entrance that makes it differ from the population as a whole. So, in this case, where we want to estimate the proportion of students who would use an expanded evening service of the campus shuttle, which sampling design is most appropriate to ensure representation from the different campuses and enrollment types, and why? The answer is Cho C, stratified random sampling with stratified campus and enrollment type, because it ensures representation from each subgroup and reduces variance. See you in the next video.

Sample Design A school board at a local community college is considering raising the student services fees. The board wants to obtain the opinion of the student body before proceeding. Design a sampling method to obtain the individuals in the sample. Be sure to support your choice.

Key Concepts

Sampling Methods

Representativeness

Sampling Bias

Watch next