Sampling methods Flashcards
What is the population?
Who were going to draw our sample from
What is a target population?
Who we want to be able to generalise our findings to
What is a random sample?
All ppt names from the target population are put into a hat or name generator, the names are drawn at random until theres enough for the sample
What is a strength of a random sample?
Reduces investigator effects, cost and time effective, high population validity as peoples’ chances of being selected is equal
What is a weakness of a random sample?
By chance you may get an unrepresentative sample
What is an oppurtunity sample?
Ppts who are available at the time and agree to take part
What is a strength of an oppurtunity sample?
Most convenient and cost/time effective
What is a weakness of an oppurtunity sample?
Low population validity so its unlikely to be representative of the target poulation, demand characteristics, researcher bias
What is a stratified sample?
A proportional representation of the target population
What is a strength of a stratified sample?
Highest population validity, reduces researcher bias
What is a weakness of a stratified sample?
It may not be fully representative as numbers may be rounded, least time and cost effective, doesn’t reflect all elements of an individual
What is a volunteer sample?
Ppts respond to an advert if they would like to take part
What is a stength of a volunteer sample?
TIme and cost effective
What is a weakness of a volunteer sample?
Volunteer bias, unrepresentative
What is a systematic sample?
Line the ppts and take the nth person
