sampling methods Flashcards
what is random sampling
picking pps using a random number generator for example
strengths of random sampling
unbiased all members of population have equal chance of selection
limitations of random sampling
can take time
what is opportunity sample
sample produced by selecting people who are easily available at the time
strengths of opportunity sample
free from researcher bias
limitations of opportunity sample
inevitably biased as sample drawn from small part of population
what is volunteer sample
people who volunteer to take part
strengths of volunteer sample
very easy to set up
limitations of volunteer sample
sample likely to be biased as pps are motivated
what is stratified sample
produced by identifying subgroups in population and creating sample with them according to their frequency in population
strengths of stratified sample
more representative
limitations of stratified sample
very time consuming
what is bias
distorted in some way
what is sample bias
when some members of population are systematically more likely to be selected in a sample than others
what is volunteer bias
idea that people who volunteer to participate in study do not represent the general population
what is mundane realism
how a study mirrors the real world. the research environment is realistic enough same events may occur in real life
what is generalisation
point of realism in psychology so results of study can be used to relate to scenarios in everyday life
what is reliability
refers to consistency findings are considered reliable if anybody doing the same study gets the same results
what is validity
a test actually tests for what it claims to
what is a pilot study
trial run of study using a small sample to see if design of experiment does what researcher wants it to do
