Sampling Flashcards
(6 cards)
what is a census ?
pros + cons
measures every number of a population
+ accurate
- expensive/time consuming
what is random sampling ?
pros + cons
to give everything the same chance of being selected
eg random number generator
+ bias free
- need to know population size
what is systematic sampling ?
pros + cons
where you take every kth unit
+ quick to do
- need to know size of population
what is stratified sampling ?
pros + cons
where the sample represents groups of a population
eg voting in the UK
+ reflect population
- population needs to have the ability to be grouped
what is quota sampling ?
pros + cons
like stratified but filled by an interviewer so like you need someone who has particular characteristics so you find someone and pick it
+ no sampling frame needed
- not random
what is opportunity sampling ?
pros + cons
quota filled by those available at the time
eg standing outside a market and interviewing the people that come out
