Sampling and Surveys Flashcards
What is a pilot study for?
To check if the questionnaire or survey ‘works’, and to fine tune your method/questions
Advantages of random sampling?
Your sample is likely to represent the target population
Disadvantages of random sampling
It can be expensive and time consuming
What are the three main methods of collecting data?
Experiment
Observation
Questionnaire
Why do we use stratified sampling?
It ensures each group is represented in proportion to its size.
What is a control group?
A group in an experiment that don’t receive treatment to allow comparison to those that do.
What is systematic sampling
Take a sample at equal intervals. This is not a random method.
What is quota sampling?
The amount of each specific group is specified, eg. 30 women are needed.
Why is quota sampling good?
It can be used when stratified sampling is impossible
Why is quota sampling bad?
It is not truly random
What is cluster sampling?
The population is divided into groups and then the groups are chosen at random.
Advantages of cluster sampling
Quicker and cheaper
Disadvantages of cluster sampling
May not be representative of the sample
What is a sampling frame
A list of everyone being sampled
What is convenience sampling
When items are selected because of convenience
