1d.07 Know the importance of identifying and controlling extraneous variables and the use of... Quiz: Pearson Edexcel Statistics, Unit 1

The 20 questions

1. What term describes a variable that is not of interest but may affect results?

   • Extraneous variable
   • Control variable
   • Dependent variable
   • Discrete variable

2. What is the main purpose of a control group in an experiment?

   • Baseline comparison
   • Maximising the mean
   • Eliminating all error
   • Increasing sample size

3. In a plant growth experiment with varying soil types, what is the soil type?

   • Target statistic
   • Extraneous variable
   • Dependent variable
   • Random sample

4. What experimental design pairs similar participants before group assignment?

   • Stratified census
   • Random quota
   • Independent groups
   • Matched pairs

5. What is the primary benefit of using a matched pairs design?

   • Increasing sample size
   • Speeding up interviews
   • Eliminating pilot tests
   • Controlling extraneous differences

6. How are conditions managed across groups in a controlled experiment?

   • Doubling them hourly
   • Keeping them constant
   • Ignoring environmental factors
   • Varying them randomly

7. Which action successfully controls an environmental variable like temperature?

   • Keeping temperature constant
   • Ignoring minor changes
   • Averaging the extremes
   • Measuring it afterwards

8. Why is it crucial to identify extraneous variables before testing?

   • Speeding up calculations
   • Ensuring normal distribution
   • Preventing misleading conclusions
   • Decreasing sample size

9. If group A tests in a quiet room and group B in a noisy hall, what is the noise?

   • Extraneous variable
   • Dependent variable
   • Target statistic
   • Control measure

10. A researcher pairs pupils by prior attainment, then gives one pupil in each pair a revision app. What design is this?

    • Systematic sample
    • Matched pairs
    • Simple random sample
    • Census

11. Why is a control group used in a medical trial?

    • Remove all bias
    • Provide baseline comparison
    • Speed up recovery
    • Increase sample size

12. Which type of study requires a control group the most?

    • Measuring classroom height
    • Testing fertiliser on crops
    • Surveying favourite colours
    • Counting daily rainfall

13. In a price trial of two shops, what is shop location?

    • Extraneous variable
    • Independent variable
    • Dependent variable
    • Random sample

14. How do you control for age when comparing school scores?

    • Randomise pupil order
    • Ignore age entirely
    • Pair pupils by age
    • Double all scores

15. When is matching pairs done in an experimental design?

    • Without any sorting
    • After final analysis
    • During data collection
    • Before random allocation

16. In a matched pairs study of 40 people, how many pairs are formed?

    • 20
    • 40
    • 80
    • 10

17. What is the main risk of not matching groups on sex?

    • Higher measurement error
    • Decreased sample size
    • Uncontrolled extraneous variable
    • Incorrect data entry

18. Which feature best controls unknown extraneous variables?

    • Purpositive sampling
    • Random allocation
    • Matched pairs
    • Stratified quota

19. What happens if room temperature differs between test groups?

    • Removes bias entirely
    • Distorts treatment effect
    • Standardises results
    • Improves data validity

20. What effect do uncontrolled extraneous variables have on validity?

    • Reduces study validity
    • Increases sample power
    • Improves data accuracy
    • Removes all bias

Related quizzes

• Know that a hypothesis can be tested only through the appropriate collection and... Quiz · 1a.01 · 20 questions
• Know the constraints that may be faced in designing an investigation to test a... Quiz · 1a.02 · 20 questions
• Determine proactive strategies to mitigate issues that might arise during the... Quiz · 1a.03 · 20 questions
• Know and apply terms used to describe different types of data that can be collected... Quiz · 1b.01 · 20 questions
• Know the advantages and implications of merging data into more general categories, and... Quiz · 1b.02 · 20 questions
• Know and apply the terms explanatory (independent) variables and response (dependent)... Quiz · 1b.03 · 20 questions
• Know the difference between primary and secondary data Quiz · 1b.04 · 20 questions
• Know the difference between population, sample frame and sample Quiz · 1c.01 · 20 questions
• Know that ‘population’ can have different meanings within a stated context Quiz · 1c.02 · 20 questions
• Know reasons for employing judgement sampling or opportunity (convenience) sampling,... Quiz · 1c.03 · 20 questions