Unit 1- Sampling methods ⭐
Opportunity sampling= is where a researcher decides to select anyone who is available and willing to participate in their study.
Random sample= all members of the target population have an equal chance of being selected)
Systematic sample= every nth member of the target population is selected.
Volunteer sample= participants select themselves to be part of the study.
Stratified sample= sub group is created based on age etc and then the population is randomly sampled within each group.
✅ This method is convenient as it saves time, effort and is less costly.
❌ sample is likely to be unrepresentative of the target population.
❌ The researcher has complete control over selection of participants, they may simply avoid people they don't like the look of (researcher bias)
❌ Very difficult and time consuming to conduct, A complete list of the target population may be extremely difficult to obtain.
❌ participants selected may refuse to take part.
✅ it is free from researcher bias . The researcher does not have an influence on who is being selected and who they think will fit their hypothesis
✅ it is usually a fair representative,
❌ If the sampling technique coincides with the frequency of the trait, the sampling technique is neither random nor representative.
✅ Avoid researcher bias. reseacher has no influence over who is chosen
✅ avoid researcher bias, the participant from the group is randomly selected
❌ can be very time-consuming dividing a sample into groups then randomly selecting from each
✅ produces a representative sample because it is designed to accurately reflect the population.
❌ requires a detailed knowledge of the population characteristics.
❌ will be bias and unrepresentative as volunteers tend to be a certain 'type of person'.
❌ this increases demand characteristics, participants may give answers to the extent they think is required.
✅ creating the sample requires little effort from the researchers