sampling

= is a subset of a population that is used to represent the entire group as a whole

we use sampling to find participants that connect to our study .

target population: group of people from whom the sample is drawn

  1. find a target population

  • this is the group of individuals the researcher is interested in e.g. people from the UK

  1. then comes sampling

  • samples will always be smaller than the population targeted

  • ideally the samples should be representative of the wider population and generalisable


O P P O R T U N I T Y

choosing participants based on their availability e.g. approaching someone in the streets,corridors, then asking them to take part in an experiment

pro: quick and easy

con: its a biased method as participants are chosen at the researcher’s discretion + participants may not be representative of the sample


R A N D O M

each member in the target population have an equal chance of being selected

e.g. placing all the names in a hat and drawing names from it

pro: it’s unbiased + partially representative

con: very time consuming, not always representative because participants who are picked may all have the same characterstics


S T R A T I F I E D

choosing participants based on their group’s percentage of a population, selecting a number of participants from a group based upon that groups proportion within the whole population

pros: highly representative because participants are being chosen in the same proportion, so the results are likely to be generalisable + reduces sampling bias

cons: time-consuming + difficult to carry out


S Y S T E M A T I C

choosing participants based on a predetermined pattern- choosing every nth name from a list of the target population

pro: very easy to do

con: can be biased + unrepresentative


V O L U N T E E R

the participants select themselves to take part in the research- advertising the experiment and stating where participants turn up if they’re interested

pros: no researcher bias + ethical because there’s informed consent

cons: volunteer bias because people who volunteer may have different characteristics to those who don’t + low representativeness, participants may not apply to the whole target population


most difficult to obtain but more representative

s y s t e m a t i c

r a n d o m

s t r a t i f i e d

v o l u n t e e r

o p p o r t u n i t y

most easiest to obtain but less representative