researchers periodically survey a few thousand of the patients taking a certain medication in order to make…
researchers periodically survey a few thousand of the patients taking a certain medication in order to make connections between that medication and the subjects general health. this method of gathering data is classified as a census. a sample survey. an experiment. an observational study.
Answer
Brief Explanations:
A census involves surveying an entire population. Here, only a few thousand patients out of all taking the medication are surveyed, so it's not a census. An experiment involves manipulating variables, which isn't the case here. An observational study just observes without intervention, but a sample survey is more specific when data is gathered from a subset (sample) of a population to make inferences about the whole population. Since a few - thousand - patient subset is surveyed to understand the whole population of patients on the medication, it's a sample survey.
Answer:
a sample survey.