Sampling Flashcards
Define population
a large group of individuals who the researcher may be interested in studying
Define target population
sub group of the general population
Define sample
group of people who take part in the research and these are people that are drawn from the target populations and need to be representative of the population
Define generalisation
the extent to which the findings and conclusions from a study can be broadly applied to the population (if sample is representative, it’s accurate)
What is random sampling?
when all the members of a target population have an equal chance of being selected
strength of random sampling
-free from researcher bias
limitation of random sampling
-time consuming
-higher refusal rates
-sample could be unrepresentative
what is systematic sampling?
when the participants are chosen by every nth term after being listen in a certain way with the population and the collection of all the nth terms are used as a sample
strength of systematic sampling
-avoids researcher bias
-representative sample
limitation of systematic sampling
-higher refusal rates
-very time consuming
what is opportunity sampling?
when you select the sample that u need by simply selecting them as they come (best example is street selection)
strength of opportunity sampling
-convenient
-less costly
limitation of opportunity sampling
-high refusal rates
-unrepresentative
-researcher has complete control over selection
what is volunteer sampling?
the participants volunteer and come to you themselves (self-selection)
strength of volunteer sampling
-easy
-minimal input from researcher
limitations of volunteer sampling
-refusal rates
-attracts a certain profile of a person
What is stratified sampling?
when the sample reflects the proportion of the people in certain subgroups within the target population
strength of stratified sampling
-avoids researcher bias
-representative sample
limitation of stratified sampling
-refusal rates
-strata cannot reflect all the ways someone is different
What are pilot studies
A small scale version of an investigation that takes place before the real investigation is conducted.
What is the aim of pilot studies
To check procedures, materials measuring scales, ect… The aim is also to allow the researcher to make changes or modifications if necessary
What is a single blind trial
When the researcher is aware that the test is being conducted but the participants aren’t . One is given a placebo and the other is given the normal one
What is a double blind test
When both the researcher and participant sis unaware
What is the difference between experimental and control group
Experimental is the group that is given the real drug and the control group is the one that is given the placebo
