Sampling Flashcards
what is a population?
the whole set of items that are of interest
what is raw data?
the information obtained from a population
what is a census?
data collected from the entire population
what is a sample?
some subset of the population intended to represent it
what is a sampling unit?
each individual thing in the population that can be sampled
what is a sampling frame?
when sampling units are individually named/numbered to form a list
what are the advantages of a census?
it should give completely accurate results
what are the advantages of sampling
- cheaper
- quicker
- there is less data to process
what are the disadvantages of a census?
- it can’t be used when testing involves destruction
- time consuming
- expensive
- there is a large amount of data to process
what are the disadvantages of sampling?
- may not be as accurate
- the sample may not be large enough to represent small subgroups
what are the types of random sampling?
- simple random sampling
- systematic sampling
- stratified sampling
how do you conduct simple random sampling?
- a sampling frame must be created using numbers or names
- then a random number generator or lottery sampling should be used to select the things that will be included in the sample
how do you conduct systematic sampling?
- sampling frame must be created
- then the required elements from the sampling frame are chosen at regular intervals until sample is created
how do you determine which item to begin with in systematic sampling?
use simple random sampling/ random generator
how do you determine the interval for systematic sampling?
divide the population size by the sample size