Data Collection Flashcards
Define census
A census is something which measures every member of a population
What is the advantage of a census?
It gives an accurate result
What is the disadvantage of a census?
It can be expensive and testing may destroy the samples
What are sampling units?
The individuals of a population
What is a sampling frame?
The full list of sampling units
What are the 3 types of random sampling?
-Simple Random Sampling
-Systematic sampling
-Stratified sampling
What is simple random sampling?
It is a system where all the units have the same chance of being selected. This can be done using random numbers or lottery sampling.
What are the advantages or disadvantages of simple random sampling?
+ bias free
- need entire sampling frame
What is systematic sampling?
-Taking every kth unit where k is the population/sample
-Pick a random number between 1 and k for the starting point
What are the advantages or disadvantages of systematic sampling?
+quick to use
-need sampling frame
What is stratified sampling?
Where the sample represents the groups (strata) of a population and is proportionate to each group.
To do this use sample/population and multiply by each strata, then sample randomly to build your sample
What are the advantages or disadvantages of stratified sampling?
+reflects population
-population must be classified in strata and this may not always be clear
What are the 2 types of opportunity sampling?
-Quota sampling
-Opportunity sampling
What is quota sampling?
Split the population into categories but instead of making the sample proportionate to the stratas, we choose a quota for each group which is filled by opportunity sampling.
What are the advantages or disadvantages of quota sampling?
+you don’t need the full sampling frame
-non-random which may include potential bias
