Sampling

• Random sampling - each member of the target population has a equal chance of being selected
• One strength of random samples is that they are unbiased
• One weakness of random samples is that it is time consuming to make a list of the entire sample
• Stratified sample - target population divided into subcategories and are selected in proportion they occur in the target population [45% men in target population = 45% men in sample]
• One strength of stratified samples is that they are more representative of the target population
• One weakness of stratified samples is it is very time consuming to calculate all relevant sub categories in the population
• Opportunity sampling - selecting participants available at the time
• One strength of opportunity sampling is that it is quick and the most economical method
• One weakness of opportunity sampling is that it is often unrepresentative of the target population
• Systematic sampling is compiling a list of the target population and choosing every nth person
• One strength of systematic sampling is avoiding researcher Bias
• One weakness of systematic sampling is that it is not as objective as random sampling , Researcher chooses order of the list and what number to choose
• Volunteer sampling is when the participants self select, often through an advert.
• One strength of volunteer sampling is it is a quick way to get a sample with the characteristics required
• One weakness of volunteer sampling is volunteer bias, volunteers more likely to be confident etc...