Sampling Flashcards
what are the 5 types of sampling?
- random
- systematic
- stratified
- opportunity
- volunteer
what is a population?
large group of individuals that a particular researcher is interested in studying
what is the target population?
subset of the general population
what is a sample?
researcher selects a smaller group from the members of the target population
- drawn to be representative
what is the aim of sampling techniques?
aims to produce a representative sample
what is the process of a random sample?
- obtain a complete list of all members of the target population
- place all names into a hat OR give all names on the list an assigned number
- take out the names of the hat until the desired number is reached OR use a random number generator util you have the desired number of ppts
what is the process of systematic smapling?
- obtain a list of the target population and arrange into alphabetical order
- every nth member of the list is selected for the sample
what is the process of stratified sampling?
- researcher has to identify the different strata that make up a population
- the proportions needed for the sample to be representative are worked out
- ppts that make up each stratum are selected using random sampling
what is the process of opportunity sampling?
- researchers takes the chance to ask whoever is around who is willing and able to take part
what is the process of volunteer sampling?
- ppts select themselves to be part of sample(self-reflection)
- researcher places an advert in a newspaper
what is a strength of random sampling?
- potentially unbiased, confounding or extraneous variables should be equally divided between groups, enhacing internal validity
what are weaknesses of random sampling?
- difficult and time-consuming to conduct(list)
- may still be unrepresentative
- selected ppts may refuse to take part
what are strengths of systematic sampling?
- objective, researcher has no influence over who is chosen
what are weaknesses of systematic sampling?
- time-consuming
- ppts may refuse to take part
what are strengths of stratified sampling?
- produces a representative sampling, generalisation becomes possible