Research Sampling Flashcards
research population
a group sharing some common characteristic, (cannot realistically study)
Sample
set of individuals that represent the population (subset)
representative sample
sample with the same characteristics as the population
biased sample
sample with different characteristics from those in the population
selection bias
survey return rate, researchers going door to door
power analysis
resource equation
E= (total nb of animals)-(total number of groups)
E is the degree of freedom of ANOVA
Non-probability sampling
population is not completely known-> difficult to identify size, 2 methods:convenience and quota
convenience sampling
sampling method where participants are easy to access and available to participate
convenience sampling examples
setting up booths, volunteers
quota sampling
identify a subgroup, then choose from each subgroup to get a quota
simple quota sampling
little is known about the characteristics of a population:
brain activity of 20 students taking NEUR course after drinking coffee : 10 in the AM, 10 in the PM
proportionate quota sampling
demographics known and proportionately represented in sample :
brain activity of 20 students taking NEUR course after drinking coffee : CUneuro program: 60% F,40%M - 12M, 8F
probability sampling
must know the exact size of population, based on random sampling
simple random sampling
all individuals have equal chance of being selected, each one independent of the other