External Validity And Sampling: RM Flashcards
Define Sampling.
A group of people who take part in a research investigation
How do you conduct Random Sampling?
- Make a list of the target population.
- Give all names a number and write these down.
- Put pieces in a hat
- Draw the pieces of paper from a hat randomly.
How do you conduct Systematic sampling?
- Create a list of the target population.
- Create a sampling frame by putting the list into a specific order (i.e. alphabetical)
- Create a sampling system (i.e. pick every 5th name)
- Use the sampling system.
How do you conduct Stratified Sampling?
- Make a list of the target population
- Create a list of specific people (groups) for the target population.
- Workout the proportions of specific groups (strata).
- Use random sampling to select the right amount of participants from each strata of target population.
How do you conduct Opportunity Sampling?
Researcher simply asks if any members of the target population to participate.
How do you conduct Volunteer Sampling?
- Place an advert where members of the target population will see it.
- People self select/ volunteer.
Define Bias.
This occurs when certain groups are either over-representative or under-representative within a sample.
Define Generalisable.
When findings and conclusions from an investigation can be applied to the target population.
Define Representative.
When a sample reflects the characteristics of the target population.
Define Sampling Technique.
A method used for creating a sample from a population.
Define Population Validity.
A type of external validity which describes how well the sample can be used to represent a target population.
Define External Validity.
A type of validity which is concerned with the extent to which research findings can be generalised outside the context of the study.
What is one strength of random sampling?
It’s representative because the sampling is random, therefore the researcher removes their own influence from who is sampled. Random sampling is representative as it limits bias in the sampling.
What is one limitation of Random Sampling?
The cost in time and money it takes to put together a list of target population.
What is one strength of Systematic Sampling?
It is representative and helps ensure there is very limited influence on who is in the sample. Reducing the likelihood of bias, making it more representative.
What is one limitation of Systematic Sampling?
It is time consuming and expensive as the process of making a systematic frame and using the sampling frame in comparison to opportunity or volunteer.
What is one limitation of Stratified Sampling?
It is time consuming and expensive, as the process of finding relevant data, working out their proportions in the target population and then going through the process of random selection. This could cause a higher demand for pay from the researcher as it takes longer time to research.
What is one strength of Volunteer Sampling?
It is relatively efficient in terms of financial cost and time as it requires minimal effort from the researcher compared to other sampling techniques. This results in less demand for pay from the researcher.
What is one limitation of Volunteer Sampling?
It could lead to an unrepresentative sample as the volunteer is bias. This is due to the fact that people that are likely to volunteer are different types of people to those who wont volunteer. This may result in an overall different type of target population.
What is one strength of Opportunity Sampling?
It is efficient in terms of time and financial costs. This is probably the least time consuming and money demanding as all the researcher has to do is ask for volunteers.
What is one limitation of Opportunity Sampling?
It c an lead to unrepresentative sampling as the researcher may pick a certain group of people as they are (eg) approachable. This limits the representation for the overall target population.
What is one strength of stratified sampling ?
It ensures that the results of the experiment are likely to be proportionally similar to the target population. Thus, the sample is representative of the population.
