census
measures every member of population
advantage of a census
accurate result
disadvantage of a cenus
expensive
what are sampling units
individuals of a population
what is a sampling frame
list of sampling units
what is random sampling
population has same chance of being selected-lottery sampling
advantage of random sampling
bias free
disadvantage of random sampling
need sampling frame
systematic sampling
take every kth unit
k=pop/sample
pick random number from 1-k
advantage of systematic sampling
quick to use
disadvantage of systematic sampling
need sampling frame