Short questions and answers

Here is the full short answer set with each question followed immediately by its answer, clean and ready to copy.


Short Answer Questions + Answers


Section 1: Survey Design & Bias

Q1

A survey asks:

“Do you support banning prayer in public schools so that teachers have more time to teach?”

a. Identify two problems with this question

b. Explain why each problem is an issue

c. Rewrite the question to make it unbiased

Answer:

a. The question is leading and double-barrelled.

b. It is leading because it suggests a benefit (“more time to teach”), which may influence respondents to agree. It is double-barrelled because it combines two ideas: banning prayer and improving teaching time.

c. A better question is: “Do you support or oppose prayer in public schools?”


Q2

Two survey questions are asked:

  1. “Should schools allow prayer?”

  2. “Should schools not allow prayer?”

a. Explain how wording may affect responses

b. Which question is more likely to confuse respondents? Explain why

Answer:

a. Wording can affect responses because slight changes may confuse respondents or lead them toward a particular answer.

b. The second question is more confusing because the negative wording can be misinterpreted.


Q3

A survey asks:

“Do you support a tax on junk food to fund programs to fight obesity?”

a. Identify the issue with this question

b. Explain how it may affect responses

Answer:

a. The question is leading.

b. The phrase “to fund programs to fight obesity” makes the tax sound beneficial, which may encourage people to support it.


Section 2: Validity, Reliability, Measurement

Q4

A survey measures academic success by asking students how confident they feel.

a. Is this valid?

b. Explain why or why not

Answer:

a. This is not valid.

b. Confidence does not directly measure academic success, so it does not capture what it is supposed to measure.


Q5

A scale gives different readings each time a person is weighed.

a. Which principle is violated?

b. Explain why

Answer:

a. Reliability is violated.

b. The results are inconsistent, so the measurement is not dependable.


Q6

Give:

a. One example of a valid categorical variable

b. One example of something reliable but biased

c. One example of something unbiased but not reliable

Answer:

a. Type of school attended (public or private).

b. “Do you agree that teachers are underpaid?” (consistent but leading).

c. “How do you feel today?” (not leading but inconsistent).


Section 3: Sampling & Representativeness

Q7

A study samples trees only along a dirt road in a forest.

a. Identify the sampling method

b. Explain why the sample may not be representative

Answer:

a. Systematic sampling.

b. The sample may not be representative because trees near the road may differ from those deeper in the forest.


Q8

A study uses volunteers who respond to an advertisement.

a. What type of sampling is this?

b. Explain one limitation

Answer:

a. Voluntary response sampling.

b. It may be biased because participants choose to take part and may not represent the population.


Q9

A study surveys 1000 people, but only 340 respond.

a. Identify the issue

b. Explain why this is a problem

Answer:

a. Non-response bias.

b. Those who respond may differ from those who do not, so the results may not represent the population.


Section 4: Margin of Error

Q10

A survey reports that 53% of people support a policy with a margin of error of ±2%.

a. Interpret this result

b. Write the interval

Answer:

a. The true population percentage is likely close to 53% within a small range.

b. The interval is 51% to 55%.


Q11

Explain what margin of error tells us about a sample result.

Answer:

Margin of error describes the uncertainty in a sample estimate and shows how close it is likely to be to the true population value.


Section 5: Variables

Q12

Classify each variable:

a. Years of tertiary education

b. Highest level of education

c. Brand of car

d. Price of last car

Answer:

a. Measurement

b. Categorical

c. Categorical

d. Measurement


Q13

Classify each as discrete or continuous:

a. Number of tries

b. Percentage of wins

c. Number of words

d. Weight

Answer:

a. Discrete

b. Continuous

c. Discrete

d. Continuous


Section 6: Experimental Design

Q14

A study allows participants to choose their treatment group.

a. What type of study is this?

b. Why is this a problem?

Answer:

a. Observational study.

b. It is a problem because participants choosing their group may introduce confounding variables.


Q15

Explain why randomisation is important in experiments.

Answer:

Randomisation helps balance confounding variables between groups, making comparisons fair.


Q16

Explain what a control group is and why it is important.

Answer:

A control group is a group that does not receive the treatment and is used as a baseline for comparison.


Q17

Explain what a double-blind study is and why it is used.

Answer:

A double-blind study means neither participants nor researchers know who receives the treatment, which reduces bias.


Section 7: Confounding & Causation

Q18

A study finds that people who drink more water perform better in exams.

a. Can causation be concluded?

b. Explain why

c. Give one confounding variable

Answer:

a. No.

b. It is observational and other variables may affect the result.

c. Study time.


Q19

Explain what a confounding variable is.

Answer:

A confounding variable affects both the explanatory and response variables, making it difficult to determine cause and effect.


Section 8: Study Types

Q20

Explain the difference between an observational study and a randomized experiment.

Answer:

An observational study observes existing differences, while a randomized experiment assigns treatments to test cause and effect.


Q21

Why can observational studies not prove causation?

Answer:

Because confounding variables are not controlled.


Section 9: Data Sleuthing (Applied)

Q22

A study does not explain how participants were selected.

Explain why this is a limitation.

Answer:

We cannot determine if the sample is representative of the population.


Q23

A study does not explain how data was measured.

Explain why this is a problem.

Answer:

Unclear measurements may reduce validity and accuracy.


Q24

A study compares two groups but does not mention differences between them.

Explain why this is an issue.

Answer:

Other differences may affect the results, making comparisons unfair.


Section 10: Interpretation

Q25

A dataset is strongly skewed to the right.

a. Which measure of centre should be used?

b. Explain why

Answer:

a. Median

b. It is not affected by outliers


Q26

Explain why the mean is affected by outliers.

Answer:

Extreme values pull the average higher or lower.


If you want next:

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