Sampling

Question 1

What is a target population

Answer 1

The group of people from whom the sample is drawn
If your sample is representative then you can generalise the results of your study to the target population

Question 2

What are the different types of sampling

Answer 2

• opportunity
• random
• volunteer
• systematic
• stratified

Question 3

Opportunity sampling

Answer 3

Consists of taking the sample from people who are available at the time of the study and fit the criteria you are looking for
✅ quick and easy to select the sample as you simply take advantage of the people that are around when you conduct your research
❌ by only using those who were present or available at the time of the study could lead to a biased sample so unlikely to be representative

Question 4

Random sampling

Answer 4

Every member of the population has an equal chance of being chosen. This involves identifying everyone in the target population and then selecting the number of participants you need in a way that gives everyone in the population an equal chance of being picked
✅ everyone in the target population has an equal chance of being selected. This means the sample should be representative as participants are selected by chance
❌ need to have a list of all members of the population and then contact all of those randomly selected

Question 5

Volunteer sampling

Answer 5

Consists if participants becoming part of a study because they volunteer when asked or in response to an advert or poster
✅ may be a relatively easy way of achieving a sample and is useful when the research requires a specific type of participant eg. Left handed
❌ unlikely to be representative of the target population. The type of volunteer may have more time, more extroverted … leading to volunteer bias

Question 6

Systematic sampling

Answer 6

When every nth member of the target population is selected
✅ unbiased as participants are selected using an objective system leading to a representative sample
❌ not truly unbiased/random unless you select a number using a random method and start with this person and then select every nth person

Question 7

Stratified sampling

Answer 7

Classifying the population into groups and then choosing a sample which consists of participants from each group in the same proportions as they are in the population, selection from the group is done using a random technique
✅ likely to be more representative than other methods because there is a proportional and randomly selected representation of subgroups
❌ very time consuming to identify subgroups and subgroups cannot reflect all the ways that people are different, so complete representation of the target population as all participants are selected by chance