data collection Flashcards
define census
measured every member of population
advantages and disadvantages of census
ad - accurate result
dis- expensive, testing may destroy
define sampling units
individulas of a population
define sampling frame
list of sampling units
types of random sampling
simple random sampling
systematic sampling
stratified sampling
define simple random sampling
to give everything same chance of being selected
use a random number/ lottery sampling
advantages and disadvantages of simple random sampling
ad - bias free
dis- need sampling frame
define systematic sampling
take every kth unit, k = pop size/samp size
pick a random number between 1 and k for starting point
advantages and disadvtages of systematic sampling
ad - quick to use
dis - need sampling frame
define stratified sampling
sample represents group (strata) of a population
(sample size / population size ) x size of strata for each strata , pick them randomly
advantages and disadvantages of stratified sampling
ad - reflects population
dis- population must be classified in strata
types of non-random sampling
quota sampling
opportunity sampling
define quota sampling
like stratified sampling but strata are filled by interview/researcher
advantages and disadvantages of quota sampling
ad - no sampling frame
dis- non-random so potential bias
define opportunity sampling
quota is filled by those available at time
