Back to Distinguish surveys, experiments, and observational studies — Problem 3 · 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.

In a tutoring experiment, one group attends tutoring (the treatment group) and the other group does not (the control group). A student says, "The control group gets nothing, so it is a pointless waste of subjects." What is the BEST correction?

The control group is the baseline the treatment is judged against; without it you could not tell whether the treatment, and not something else, caused a change.

The student is right; the control group does nothing useful and could be dropped.

The control group should also receive the treatment so the study is fair.

The control group matters only if it is larger than the treatment group.