Sampling Flashcards
What is a target population?
As the participants are the people who are selected to take part in the study come from a much larger group known as the target population.
Example: If a sample is taken of a group of men aged 30-60 living in London men in this age group and any concussions should only be applied to this target population.
What is a sample?
A sample is a group of people who take part in the research investigation. (It will be drawn from the target population, it’s presumed to be repetitive of the population.
Advs and Disadv of sample sizes?
If the sample is too big you will waste a lot of time and money carrying it out.
If the sample is too small, you can’t make a proper generalisation from it.
An ideal sample size could be 30-50 participants but it really does depend on what you are studying.
The sample size really depends on what you are studying and how you are carrying out that research. For example: if it was online, there could be a massive sample. Also could have to be sent to a lot of people as some people ignore it.
What is generalisation?
a general statement or concept obtained by inference from specific cases.
If a research sample is properly constructed this gives you an ability to generalise any results and conclusion about them onto the target population from which your sample came.
what are the 4 different types of sampling?
Random
Snowball
Self-selected/ volunteer
Opportunity
what is opportunity sampling? Advs and disadvs?
Opportunity sampling is when a researcher selects whoever is willing and available at the time.
Adv
Quick and easy way of selecting participants.
Disadv
Selected participants may not be representative outside the research situation.
What is Self selected / Volunteer sampling? Advs and disadvs?
Self selected / Volunteer is participants that put themselves forward to take part in the study.
Adv
Easy, Cheap and quick, all that is needed is an advertisement for participants.
Disadv
Selected participants may not be representative as only certain people, e.g. the elderly, will volunteer
What is random sampling? Advs and disadvs?
Random sampling is a sampling method in which all members of a group have an equal and independent chance of being selected.
Adv
Can be used with large sample populations
Avoids bias
Disadv
Can lead to representation of the overall target population or area if large areas are not hit by the random numbers generated. This is made worse if the study area is very large.
There may be practical constraints e.g. amount of time/ access to certain parts of the study area.
Is it done correctly? Are the samples chosen completely random? Human error/ interference.
What is Snowball sampling? How does it work? Advs and Disadvs?
Snowball sampling is used when you require a specific/ specialised group of people but they can only be found few and far between.
How it works:
A Psychologist will find 1 participant and study them then they will ask if they know someone who is in the same situation as them and would they be interested in taking part in the research.
This then carries on snowballs! Because more and more people can be added to the sample by asking the previous participants if they know.
This can be useful when the psychologist wants very niche or specialised information gathered.
Adv
The sample could be bias (after you are asking for recommendations from last participant)
Disadv
Often it’s the only way to get information only from certain groups of people (think of particularly deviant/ criminal groups.. It’s really diffcuilt for a psychologist to ordinarily get access to these types of groups)
