Sampling methods Flashcards
probability sampling methods
samples in which each element of the population has a known, nonzero likelihood of selection
non-probability sample
samples in which specified elements from the population have been selected in a non-random manner
simple random error
assigning a number to every element of the population and then using a table of random numbers to select specific elements for the inclusion of the sample –> SS/PS
Systematic sampling
probability sampling in which the entire population is numbered, and elements are selected using a skip interval
skip interval
PS/SS
stratified sampling
ensuring all the subgroups (strata) are represented in the sample
proportional allocation
elements selected for the stratum is directly proportional to the size of the stratum relative to the size of the population
disproportional/ optimal allocation
elements selected are proportional to the relative size of the stratum and and the standard deviation of the characteristic under consideration
cluster sampling
sampling units are selected from a number of small geographic areas to reduce data collection costs
multi-stage area sampling
geographic areas are selected in progressively smaller population units
convenient sample
using people have are easily accessible
judgement sample
researchers judgement about representativeness of the population under study
quota sample
sample has the same proportions of individuals as the entire population with respect to traits/characteristics
snowball samples
additional respondents are selected based on referrals from initial respondents
