Sampling Flashcards
Define sampling
The method used to select participants such as random ,opportunity or volunteer sample or to sample behaviours in an observation such as time sampling
Define random allocation
An attempt to control for participant variables in an independent groups design which ensures that each participant has the same chance of being in one condition as any other
Define standardisation
Using exactly the same formalised procedures and instructions for all participants in a research study
What is a pilot study ?
Small scale version of your study to ensure :
- the design works
- participants understand instructions
- if you have missed anything
- validity and reliability
Define population
The group of people from whom the sample is drawn
We use a target population if we want to investigate specific individual differences
Define sample
The people the researcher actively uses in the research
Define opportunity sampling
Involves a sample of participants produced by selecting people who are most easily available at the time of study
Define random sampling
Involves a sample of participants produced by using a random techniques such that every member of the target population being tested has an equal chance of being selected
Define systematic sampling
Involves a sample being obtained by selecting every nth person and can be a random sample if the first person is selected using a random method and then select every nth person after that
Define stratified sampling
Involves a smoke of participants produced by identifying subgroups according to their frequency in the population and then participants are selected randomly from the subgroups
Define volunteer sampling
Involves a sample of participants that relies solely on volunteers to make up the sample
What is a advantage of random sampling
Unbiased
All members of the target population have an equal chance of selection
What is a disadvantage of random sampling ?
- researcher may end up with a biased sample because the sample is too small
- subgroups of target population might not be selected does not guarantee a representative sample
- need to possess a list of all members of the population and then contact all those selected which may take some time
What is a advantage of opportunity sampling ?
Easy and fastest method because you just us the first participants you can find
What is a disadvantage of opportunity sampling ?
Biased because the sample is drawn from a small part of the target population
unlikely to be representing of a target population
What is a advantage of volunteer sampling ?
- Quick , convenient and ethical if it leads to informed consent
- large response rate
- allows more in depth analysis and accurate results
What is a disadvantage of volunteer sampling ?
- Sample is biased because the participants are likely to be more highly motivated
- eg. Getting paid , eager to be helpful, extra time on their hands
What is a advantage of systematic sampling ?
avoids bias as once the researcher has decided what number they have no control over who is being selected
What is a disadvantage of systematic sampling ?
- not completely objective because the researcher may decide on how people are listed before the selection
- there is a small chance of a ‘freak’ sample which would not be representative
What is a advantage of stratified sampling ?
more representative than an opportunity sample because there should be equal representation of subgroups
What is a disadvantage of stratified sampling ?
- it is time consuming because all potential participants need to be assessed and categorised
- some groups within a sample may not be represented if a small samples is used
What is the Hawthorne effect ?
If people are interested in something and in the attention they are getting them they show a more positive response and try harder at tasks
- results are artificially high = could lead to invalid conclusions
- opposite occurs if participants are uninterested
What are demand characteristics ?
There are aspects of the study that allow participants to form an idea about its purpose
If they know what response the researcher is expecting they may respond to “please” them
Causes the data to become invalid
What is social desirability bias ?
People try to show themselves in the best possible light
They may not complete a task truthfully and give the answers that are more socially acceptable
Results become less valid
What is researcher bias ?
The researchers expectations can influence how they design their study and how they behave towards the participants
- Expectations - measurement and analysis
- hypothesis might be false
- may focus on amassers that fit their expectations
What is investigator bias ?
Anything the researcher does that affects how the participant behaves
- demand characteristics
- could lead to them asking leading questions
- participants may react to the behaviour or appearance of a researcher and respond differently
What is a unstructured observation ?
Researcher writes down everything they see tends to produce accounts of behaviour rich in detail
What is a structured observation ?
Allows the researcher to quantify their observations using pre-determined list of behaviours and sampling methods
What are behavioural categories ?
When a target behaviour is broken up into components that are observable and measurable
What is time sampling ?
A target individual or group is first established then the researcher records their behaviour in a fixed time frame
Advantage of time sampling ?
Economical In time and effort
Disadvantage of time sampling
Some behaviours will be missed and thus the observation may not be representative
What is event sampling ?
A target behaviour or event is first established then the researcher records this event every time it occurs
Example of event sampling
How many times a person smiles in a 10 min period
Advantage of event sampling
Able for recording infrequent behaviours
Disadvantage of event sampling ?
If too many observations happen simultaneously it may be difficult to record everything
