Key Idea: Each research method answers a different kind of question. Experiments show cause; the others describe, relate or explore.
Change something
- Experiment: set an IV, measure a DV, control the rest
- True: random allocation. Quasi: groups already exist
- The only method that can show cause
Watch or measure
- Observation: record behaviour, change nothing
- Correlational study: relate two variables
- Case study: one case, several methods
Ask
- Survey: the same written questions for many
- Interview: structured, semi-structured, unstructured
- Focus group: a guided group discussion
Who is studied
- Random, stratified: chance decides
- Opportunity, self-selected, snowball: it does not
- Sampling bias limits how far findings apply
The words to know
| Word | What it means |
|---|---|
| Independent variable | What the researcher changes in an experiment |
| Random allocation | Chance decides who goes into which condition |
| Naturalistic observation | Watching behaviour in its everyday setting |
| Inter-rater reliability | How closely two observers' records agree |
| Triangulation | Using more than one source to check the findings |
| Correlation coefficient | A number from -1 to +1: direction and strength of a link |
| Self-reported data | What people tell a researcher about themselves |
| Leading question | Wording that pushes people towards one answer |
| Representative sample | A sample with the same mix as the target population |
Name the method. Say what it can show and what it cannot. Tie both to the study in front of you.
Exam-style question
Your class practical was an interview. Each student interviewed one classmate about how much sleep they get and how it affects their schoolwork. Compare and contrast the research methodology of the interview used in your class practical with the research methodology of an experiment.
Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
Important: Only an experiment with random allocation supports the word causes. For an observation, a survey, a correlation or a case study, write is linked to or suggests.
Tap each card to check yourself.
Does caffeine speed up reactions? Which method? An experiment: caffeine can be given to one group and not another.
How do children play at break? Which method? A naturalistic observation with a checklist.
Is time online related to mood? Which method? A correlational study, often using survey data.
What is it like to change school at sixteen? Which method? Semi-structured interviews: the person's own account.
One patient with a rare memory loss. Which method? A case study.
Students answer a poster asking for volunteers. Which sampling technique? Self-selected sampling.
Exam tips
- For any method, know one thing it can show and one thing it cannot.
- Use the method's own words: IV and DV, behavioural categories, open and closed questions, r.
- Say how the sample was found, and who was left out.
- In a comparison, put both methods in the same sentence.