Sampling Methods Flashcards
What is the definition of a sample?
A selection of observations taken from a sample of a population to research information about the population.
What’s a census?
A research into every member of a population.
Name the advantages and disadvantages of a census.
Ad: Gives an accurate result
DIs: Time consuming, cant be used if data is going to be destroyed and is hard to process loads of data.
Name the advantages and disadvantages of a sample:
Ad- Less time consuming, fewer data to handle and less data to process.
Dis- Data may not be accurate and doesn’t represent the whole population.
What is a simple random sample:
Where you allocate each person in a sample with a number of y - z, you then gather your x amount of numbers needed for the sample using a random number generator and then match these numbers according to the ones in the y-z sample.
What are the Advantages and Disadvantages of a simple random sample:
Ad: Free of bias, easy and cheap to obtain and each sample has an equal chance of selection,
Dis: Not suitable for large sample sizes and a sampling frame is needed.
What is a systematic sample:
Where the sample is chosen at regular intervals, for instance if you needed 20 people from 100 people every 5th person would be selected.
What are the Advantages and Disadvantages of a systematic sample:
Ad- Simple and quick to use and is effective for large sample sizes.
Dis- Sampling frame is needed and is subject to bias.
What is a stratified sample:
Where a population if divided into a mutually exclusive strata and a random sample is taken.
What are the advantages and disadvantages of a stratified sample:
Ad- Accurately reflects the whole population and guarantees proportional representation.
Dis- Must be classified into clear distinct strata and has the same disadvantages as simple random sampling (not suitable for large population size and sampling frame is needed)
What is quota sampling:
Where a population is divided into a group according to a given characteristic, the size of the group determines the proportion of sample used, the are then interviewed and classified into the appropriate quota.
What are the Advantages and Disadvantages of a Quota Sample?
Ad- Allows a small sample to still be representative, no sampling frame needed, quick and easy and is easy to compare between different groups.
Dis- Could introduce bias, could be costly dividing into groups, Non responses aren’t recorded and increased scope study time requires expertise.
What is opportunity sampling:
Where the sampler picks the first people available to take the sample.
What are the advantages and disadvantages of this-
Ad- Easy to carry out and inexpensive.
Dis- Not proportional and highly dependent on researcher.
What is quantitative data and qualitative data:
Quantitative Data: Data associated with numerical data (Height, time, shoe size)
Qualitative Data: Data associated with non-numerical data (Eye colour, Hair colour, shoe colour etc)
