Planning research
- Research starts with an aim or a hypothesis. A pilot study (a small trial run) checks the method works.
- The target population is the group being studied; a sampling frame is a list of the members of the population.
Sampling methods
- Random sampling: everyone has an equal chance of being chosen.
- Systematic sampling: choosing every nth person from the sampling frame.
- Stratified sampling: dividing the population into groups (such as by age or gender) and sampling from each in proportion.
- Quota sampling: choosing a set number of people from each group, without a sampling frame.
- Snowball sampling: participants suggest others, useful for hard-to-reach groups.
- A representative sample allows findings to be generalised to the whole population.
Reliability, validity and ethics
- Reliability: whether the research would get the same results if repeated.
- Validity: whether the research gives a true picture of what it studies.
- Ethics: informed consent, confidentiality and anonymity, avoiding harm, avoiding deception where possible, and the right to withdraw.
Key terms
- Pilot study
- A small trial run of research.
- Sampling frame
- A list of the members of the target population.
- Stratified sampling
- Sampling from groups in proportion to the population.
- Snowball sampling
- Participants suggesting other participants.
- Representative sample
- A sample that reflects the population.
- Generalisation
- Applying findings to the wider population.
- Reliability
- Whether research would get the same results if repeated.
- Validity
- Whether research gives a true picture.
Practise The research process, sampling and ethics: 10 questions