Collecting Data unit test
A test on this unit alone, marked as a percentage and a letter grade — for the test your class is actually sitting, rather than for May. Answer everything, then submit once: seeing the answer to question 3 before attempting question 4 makes the final percentage meaningless.
Matched pairs design
Response bias
Three principles of experimental design
Placebo and control group
Experimental units vs subjects
Stratified random sample
Blinding and placebo effect
Systematic sample
Undercoverage
Convenience and voluntary response samples
Population vs sample
Why blocking is not the same as stratifying
Short answer 1. Define or explain: Random assignment vs random selection
3 ptsShort answer 2. Define or explain: Describing a sampling procedure fully
3 ptsShort answer 3. Define or explain: Why a large biased sample is worse than a small random one
3 ptsShort answer 4. Define or explain: Completely randomized vs block design
3 ptsFree response
8 ptsA researcher has 60 tomato seedlings and wants to compare the effect of two fertilizers (A and B) on total tomato yield. Half of the garden receives full sun and the other half is partly shaded.
Describe a completely randomized design for this experiment.
Explain the purpose of random assignment in this experiment.
A colleague suggests blocking by sunlight instead. Describe how the randomized block design would work and explain why it might be preferable here.
Suppose the block design shows a significantly higher mean yield for Fertilizer A. Discuss what can and cannot be concluded, including whether the result generalizes beyond this study.