Flashcards
statistics chapter 1 sample definitions
Flashcards do conjunto (20)
- 1what is a Population?a population is a whole set of items that are of interest
- 2what is a censusa census observes or measures every member of a population
- 3what is the advantage of a census?it should give a completely accurate result.
- 4what are the disadvantages of a census?- time consuming and expensive
-can not be used in testing when the process destroys the item
-Hard to process large quantities of data - 5what is a sample?a selection taken form a subset of the population which is used to find out information about the population as a whole.
- 6advantages of a sample?less time consuming and expensive than a census
-fewer people have to respond
-less data to process than in a census - 7what are the disadvantages of a sample?data may not be as accurate
sample may not be large enough to give information about small subgroups of the population - 8what is systematic sampling?where the required elements are chosen at regular intervals from an ordered list
- 9what is stratified sampling?one where the population is divided into mutually exclusive strata and a random sample is taken from each.
- 10what are the advantages of simple random sampling?-free of bias
-easy and cheap to implement for small populations and small samples
-each sampling unit has a known and equal chance of selection - 11what are the disadvantages of simple random sampling?-Not suitable when the population size or the sample size is large, as it is potentially time consuming, disruptive and expensive
-A sampling frame is needed. - 12what are the advantages of systematic sampling?-simple and quick to use
-suitable for large samples and large populations - 13what are the disadvantages of systematic sampling?-a sampling frame is needed
-it can introduce bias if the sampling frame is not random - 14what are the advantages of stratified sampling ?-sample accurately reflects population structure
-guarantees proportional representation of groups within a population - 15disadvantages of stratified sampling?-population must be clearly classified into distinct strata
selection within strata suffers same disadvantages as simple random sampling - 16what is quota and opportunity sampling? (non random)quota sampling, where a researcher selects a sample that reflects that characteristics of the whole population
opportunity sampling, taking a sample from whatever is available at the time - 17benefits of quota sampling?allows a small sample to still be representative of the population
allows for easy comparison between different groups - 18disadvantages of quota sampling?non random sampling introduces bias
population must be divided into groups which can be costly or inaccurate. - 19advantages of opportunity sampling?easy to carry out
inexpensive - 20disadvantages of opportunity sampling?unlikely to provide a representative sample
highly dependent on individual researcher
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- Highers Maths (statistics 1) FlashCards sobre statistics chapter 1 sample definitions, criado por Daniel Nnajiuba em 21-08-2020.
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- Daniel Nnajiuba
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