sampling Flashcards
what is a population?
the large group of individuals that a researcher is interested in studying
what is a sample?
a group of people who take part in a research investigation.
what is a sample presumed to be?
from a target population and representative
what is bias (in terms of sampling)
when certain groups are underrepresented within the selected sample
what is generalisation?
the extent to which findings from an investigation can be applied to the rest of the population
what is a random sample?
a form of sampling in which all members of a target population have an equal chance of being chosen
how do you do a random sample?
- obtain a list of all members from target population
- assign all members on the list a number
- select participants through a form of lottery method
what is a systematic sample?
every nth member of a population is selected (e.g. every 3rd person)
how do you do a systematic sample?
- produce a sampling frame (list of people in population organised into some order)
- nominate a sampling system (i.e. every 6th person
- work though sample until it is complete
what is a opportunity sample?
ask random people of they are available and willing to take part in an experiment (e.g. people in the street)
what is a stratified sample?
where the composition of the sample reflects the proportions of people on the subgroups within the target population.
how do you do a stratified sample?
- identify the different subgroups
- work out the proportion needed for the sample to be representative
- the participants that make up the proportion of each subgroup are chosen using random sampling.
(check notes for example)
what is volunteer sampling?
participants select themselves to be apart of the sample
how do you do a volunteer sample?
-place an advert in a newspaper or a notice board
or
- participants raise hands when researcher asks
