Question 1

Which of the following best describes an experiment in the context of data collection?

Accepted Answer

Applying a change, measuring its effect, and assuming causation.

Question 2

A medical researcher gives 15 subjects a placebo and 15 subjects a medication, then measures their blood pressure. What type of study is this, and can causation be assumed?

Accepted Answer

Experiment; causation can be assumed.

Question 3

A manager surveys employees about their job satisfaction after a new policy is implemented, but does not assign the policy randomly. What type of study is this?

Accepted Answer

Observational study

Question 4

Which of the following scenarios allows you to infer causation?

Accepted Answer

A scientist randomly assigns subjects to receive either a new drug or a placebo and measures their recovery rates.

Question 5

A store surveys its target demographic and finds that 80% would purchase a product after heavy advertising. Can they conclude the advertising caused the high percentage of interest?

Accepted Answer

No, because this is an observational study and causation cannot be assumed.

Question 6

Which of the following is NOT a characteristic of an observational study?

Accepted Answer

Causation can be assumed.

Question 7

A software company randomly assigns users to test a new app feature and measures their engagement. What type of study is this?

Accepted Answer

Experiment

Question 8

A researcher rolls a fair die 100 times and records the outcomes. Is this an experiment or an observational study?

Accepted Answer

Experiment

Question 9

Which of the following best explains why causation cannot be assumed in an observational study?

Accepted Answer

Because there may be confounding factors that are not controlled.

Question 10

A manager wants to test whether increasing store hours increases profits. They randomly select half of the stores to increase hours and compare profits after one month. What type of study is this?

Accepted Answer

Experiment

Question 11

Suppose a researcher wants to determine if a new teaching method improves student performance. They randomly assign students to either the new method or the traditional method and compare test scores. What is the main advantage of this approach?

Accepted Answer

It allows for the assumption of causation due to random assignment.

Question 12

Which of the following is a key difference between an experiment and an observational study?

Accepted Answer

Experiments involve random assignment and manipulation of variables.

Question 13

A nutritionist observes the eating habits of 100 people and records their cholesterol levels. What type of study is this?

Accepted Answer

Observational study

Question 14

Which of the following statements is true regarding causation in experiments?

Accepted Answer

Causation can be assumed if random assignment and control are used.

Question 15

A company wants to know if their new advertising campaign increases sales. They compare sales before and after the campaign without random assignment. What type of study is this?

Accepted Answer

Observational study

Question 16

Which of the following is an example of a multi-step experimental design?

Accepted Answer

Randomly assign subjects to two groups, apply a treatment to one group, measure outcomes, and compare results.

Question 17

A researcher wants to study the effect of caffeine on reaction time. They randomly assign participants to receive either caffeine or a placebo, then measure reaction times. What type of study is this?

Accepted Answer

Experiment

Question 18

Which of the following best describes the process of random assignment in experiments?

Accepted Answer

Assigning subjects to groups using a random process to reduce bias.

Question 19

A school wants to know if a new lunch program affects student health. They implement the program in one school and compare health outcomes to another school without the program. What is a potential issue with this design?

Accepted Answer

There may be confounding variables between the two schools.

Question 20

Which formula represents the probability of rolling a 6 on a fair six-sided die?

Accepted Answer

$$P(6) = \frac{1}{6}$$

Introduction to Collecting Data: Experimental and Observational Studies

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