Back to Distinguish surveys, experiments, and observational studies — Problem 2 · Task Set 14

Exercises: Distinguish Surveys, Experiments, and Observational Studies

Work through each section in order. For classification problems, decide
whether a study is a sample survey, an observational study, or a randomized
experiment, and use two separate questions: "Was there random SELECTION?"
(which governs whether results generalize to a population) and "Was there
random ASSIGNMENT?" (which governs whether a difference can be read as
causation). For explanation problems, write in complete sentences.

Grade 10·21 problems·~35 min·Common Core Math - HS Statistics and Probability·group·hss-ic-b-3

Work through problems with immediate feedback

Warm-Up: Study Vocabulary

These problems review the vocabulary you will use throughout.

Researchers compare the test scores of students who CHOSE to attend tutoring against students who chose not to. No one was assigned to a group; the researchers only watch the groups that already exist. What kind of study is this?

An observational study, because it compares pre-existing groups without imposing a treatment.

A randomized experiment, because two groups are compared.

A sample survey, because no treatment is imposed.

It is not a study, because the groups were not assigned.