Mathematics, A-level Statistics, Advantages and disadvantages of sampling types

Disadvantages of systematic sampling

A sampling frame is needed It can introduce bias if the sampling frame is not random

Advantages of quota sampling

Allows a small sample to still be representative of the population No sampling frame required Quick, easy and inexpensive Allows for easy comparison between different groups within a population

Advantages of opportunity sampling

Easy to carry out Inexpensive

Disadvantages of a census

Expensive Time consuming Lots of data to handle Difficult to ensure the whole population is being used

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

Advantages of using a sample

Less time consuming and expensive than a census Fewer people have to respond Less data to process

Advantages of random sampling

No bias Clear how the sample is chosen, process can be explained

Disadvantages of quota sampling

Non-random sampling can introduce bias Population must be divided into groups, which can be costly or inaccurate Increasing scope of study increases number of groups, which adds time and expense Non-responses are not recorded as such

Disadvantages of simple random sampling

Not suitable when the population size or the sample size is large A sampling frame is needed

Disadvantages of stratified sampling

Population must be clearly classified into distinct strata Selection within each stratum suffers from the same disadvantages as simple random sampling

Advantages of stratified sampling

Sample accurately reflects the population structure Guarantees proportional representation of groups within a population

Disadvantages of non-random sampling

Samples are likely to be unrepresentative Researcher may be swayed by their impressions of people

Advantages of a census

Should give a completely accurate result

Advantages of systematic sampling

Simple and quick to use Suitable for large samples

Disadvantages of random sampling

Some people might not want to take part in the study A sampling frame is needed

Disadvantages of using a sample

The data may not be accurate The sample may not be large enough to give information about small sub-groups of the population

Disadvantages of opportunity sampling

Unlikely to provide a representative sample Highly dependent on individual researcher

Advantages of non-random sampling

Useful when there's no sampling frame Useful if a group is difficult to reach