WJEC A-Level Psychology 601-5719-7
Psychology Past to Present — The Five Approaches
Contemporary Debates
Principles of Research and Application of Research Methods
Mathematical Requirements for Psychology (Appendix A: AS Unit 2 and A2 Unit 4)
Addictive BehavioursAddictive
Autistic Spectrum BehavioursAutistic spectrum
Bullying BehavioursBullying
Criminal BehavioursCriminal
SchizophreniaSchizophrenia
StressStress
Controversies in Psychology
Applied Research Methods
Principles of Research and Application of Research Methods
Levels of Measurement: interval data and ratio data
- 3 things to know
- AS Unit 2
Overview
Recall questions on interval data and ratio data.
What you need to know
Answer each one before you reveal it.
Define ratio data.
What property does interval data have that ordinal data lacks?
Questions from this subtopic
Each one with the model answer underneath.
- 1
What property does interval data have that ordinal data lacks?
Model answer
Interval data are measured on a scale with equal, fixed intervals, so the difference between any two adjacent points is the same size.
- 2
State one example of interval data used in psychology.
Model answer
A score on a standardised intelligence test.
- 3
Why is an interval scale said to have no true zero?
Model answer
Its zero point is arbitrary rather than meaning a complete absence of the quality being measured, so a score of zero does not mean the person has none of it.
- 4
Define ratio data.
Model answer
Ratio data are measured on a scale with equal intervals and a true zero point, so zero means that none of the quantity is present.
- 5
Give two examples of ratio data from psychological research.
Model answer
Reaction time in seconds and the number of words recalled from a list.
- 6
Why can you say a reaction time of 0.8 s is twice as long as one of 0.4 s, but not that a test score of 140 shows twice the intelligence of a score of 70?
Model answer
Reaction time is ratio data with a true zero, so ratios are meaningful, whereas the test score is interval data with an arbitrary zero and cannot be compared as a multiple.
Other ways to work this
The same content, four other ways.
What is inside Levo
Six ways to work the same material.
Every question in Principles of Research and Application of Research Methods, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
Or £46 a year, about £3.83 a month. Cancel anytime.