Selection Of Participants Flashcards
What is opportunity sampling?
Taking the sample from people who are available at the time the study is carried
What is random sampling?
Every member of the population has an equal chance of being chosen
What is volunteer sampling?
When ppts volunteer in response to an advert
What is systematic sampling?
Statistical method by which the researcher randomly picks the first item or subject then selects nth subject from the list
What is stratified sampling?
Classify population into categories and then choose a sample consisting of participants from each category in the same proportion as in the population
Advantages and limitations of opportunity sampling
Can be the most straight forward as you use people who are readily available to you
Cheap
Can produce a biased sample
Ppts may decline so becomes self selected study
Advantages and limitations of random sampling
Provides unbiased sample
Very time consuming
Hard with large population
Advantages and limitations of volunteer sampling
Reach wide variety and unusual people
Usually biased as the ppts are more highly motivated or have more time on their hands
Demand characteristics may be shown
Advantages and limitations of systematic sampling
Degree of system or process to random selection
Population is evenly sampled
Can interact with hidden periodic trait within population
Advantages and limitations of stratified sampling
Sample should be representative of whole population
Time consuming (categories identified and classified) Need lots of info on target population
Advantages and disadvantages of using the mean
Uses all the data
Only used with interval or ratio data
Affected by anomalies
Advantages and disadvantages of using the median
Can be used with ordinal data
Remains relatively unaffected by extreme outliers
Doesn’t work well with small data sets
Can produce different averages when only one figure in the data set changes
Advantages and disadvantages of using the mode
Useful when data is in categories
Not widely used in psychological research
Small changes have a big effect
Might not be a repeated number
Advantages and disadvantages of using the range
Easy to calculate
Doesn’t provide any answers about the distribution of numbers
Very effected by extreme outliers
Advantages and disadvantages of using standard deviation
More sensitive that range
May hide some characteristics such as extreme values
