Problem-Solving and Data AnalysisVery hardRandom selection and random assignment together
Problem-Solving and Data Analysis practice question
Researchers selected 400 students at random from all students enrolled at one university and randomly assigned each of them to take notes either by hand or on a laptop during the same series of lectures. Students who took notes by hand scored significantly higher on a later comprehension test.
Which conclusion is best supported?
- A. For students at that university, taking notes by hand caused the higher comprehension scores.Correct
- B. For students at universities generally, taking notes by hand causes higher comprehension scores.
- C. Among students at that university, note-taking method and comprehension are associated, but no causal conclusion is possible.
- D. No conclusion is possible, because the study involved only one university.
Answer: A. For students at that university, taking notes by hand caused the higher comprehension scores.
This study has both features, and each buys something different. Random ASSIGNMENT to the two methods supports a causal conclusion; random SELECTION from that university's students supports generalising to that university. Together they give a causal claim about students at that university.
Why the other answers are wrong
- B. For students at universities generally, taking notes by hand causes higher comprehension scores.
- The random selection drew only from one university's students, so the generalisation stops there. Students elsewhere had no chance of being selected and may differ.
- C. Among students at that university, note-taking method and comprehension are associated, but no causal conclusion is possible.
- Random assignment is present, and that is precisely what licenses a causal conclusion. This answer applies the caution appropriate to an observational study to an experiment.
- D. No conclusion is possible, because the study involved only one university.
- One university limits how far the result generalises, but it doesn't void the study. Within that university the design supports a strong causal conclusion.
More Problem-Solving and Data Analysis questions
- Very hard
An item priced at $200 is first marked down by 20%, and then an additional 10% is taken off the reduced price.… - Very hard
A data set of 6 test scores has a mean of 78. After a 7th score is added, the mean rises to 80. What was the 7… - Very hard
If one of the chips that failed inspection is selected at random, what is the probability that it was produced… - Very hard
The regular price of a bicycle at a shop was increased by 25%. Later, during a sale, this increased price was … - Very hard
What is the result when the mean number of pets is subtracted from the median number of pets? - Very hard
What is the value of x?
Not affiliated with the College Board. SAT is a trademark of the College Board.