Survey, experiment or study? worksheets

Half the plants, chosen at random, are given the new fertilizer. Runners who already train daily are compared with those who do not. One of those is an experiment and the other is not, and the difference is a single word.

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Survey, experiment or study?

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What's on this sheet

Every question on these free printable worksheets is settled by asking one thing first: was anything DONE to anybody? If a researcher decided who got what, and decided it at random, it is an experiment — and that assignment is the only reason an experiment can claim one thing caused another. If nothing was assigned, the sentence is either asking people something, which is a sample survey, or measuring an outcome in groups that were already different, which is an observational study.

Why this sheet works

The order of those two questions is the point. Reaching for "observational" first is how a student calls a randomized trial an observation: nobody in the sentence looks like they are being experimented on, and the word "randomly" gets read as random SELECTION rather than random assignment. Assignment is checked before anything else, on every question and in the worked walk.

How this one works

Ask first whether anything was assigned

was anything assigned?

not assigned

Observational study

Runners who already train daily are compared with those who do not. Start with the one question that settles it: was anything DONE to anybody?
Nothing was done to anyone. The groups in the sentence were already different before anybody looked. Nobody is being asked a question either; an outcome is being measured in groups that formed themselves.
The groups were ALREADY different; nobody assigned the training.

Reading a studySurvey, experiment or study

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