Sampling Flashcards
What is a random sample?
All members of the population have an equal chance of being selected, you gather a list and then use a lottery method (names out of a hat) to get your sample.
What is systematic sampling?
When every nth number of the population is selected and generates a sample this way.
What is a stratified sample?
The composition of the sample reflects the proportions of people in certain subgroups within the target population or the wider population. Then you randomly select your sample from this.
What is an opportunity sample?
When researchers decide to select anyone who happens to be willing and available.
What is a volunteer sample?
Involves participants selecting themselves to be part of the sample, a researcher may place an advertisement in a newspaper etc to gather their sample.
What is a strength of random sampling?
The sample is potentially unbiased, the confounding and extraneous variables should be equally divided, enhancing internal validity.
What is a limitation of random sampling?
Random sampling is difficult and time-consuming to conduct, a complete list of the target population may be extremely difficult to obtain.
What is a strength of systematic sampling?
The sampling method is objective, once the system for selection has been established the researcher has no influence over who is chosen.
What is a limitation of systematic sampling?
This method is time-consuming and participants may refuse to take part, resulting in a volunteer sample.
What is a strength of a stratified sample?
It produces a representative sample because it is designed to accurately reflect the composition of the population, meaning the findings can be generalised.
What is a limitation of a stratified sample?
The identified strata cannot reflect all the ways that people are different, so a complete representation of the target population is not possible.
What is a strength of an opportunity sample?
This method is convenient and and much less costly in terms of time and money because a list of members of the target population is not required.
What is a limitation of opportunity sampling?
There is 2 types of bias; 1) the sample is not representative of the target population so findings cannot be generalised. 2) there is researcher bias as they have complete control over who they select.
What is a strength of a volunteer sample?
It’s less time-consuming and requires minimal effort from the researcher and they end up with participants that are more engaged.
What is a limitation of a volunteer sample?
Volunteer bias is a problem as you may attract a certain profile of people that are more curious and more likely to try and please the researcher, meaning the findings cannot be generalised.
