Research methods (experimental) Flashcards
What are the 3 types of experiment methods?
-lab
-field
-natural
Features of a lab experiment.
- Artificial setting
- Control over extraneous variables so we can see if IV causes DV
- Looks for a difference between 2 conditions
Features of a field experiment.
- Real life setting but researcher still manipulated the IV to see effect on DV
- Looks for difference between 2 conditions
Features of a natural experiment.
- A study that examines a naturally occurring variable in a real-life situation.
Advantages of a lab experiment.
- High internal validity
- Easy to replicate
Disadvantages of a lab experiment.
- Low ecological validity
- demand characteristics
Advantages of a field experiment.
- High ecological validity
- Less demand characteristics
Disadvantages of a natural experiment.
- Low internal validity
- Cannot replicate
Advantages of a natural experiment.
- High ecological validity
- No demand characteristics
Disadvantages of a field experiment.
- Low internal validity
- Hard to replicate
What is independent variable?
The IV is the variable that we are investigating and we change between conditions
What is dependent variable?
The DV is the variable that we are measuring and remains the same in both conditions
What is a one-tailed hypothesis?
This is directional as it states exactly which way the results will go
What is a two-tailed hypothesis?
This is non-directional as it states there will be a difference between the conditions, but does not state how
What is a null hypothesis?
No difference it states there will be no significant difference between the conditions
What is the target population?
The group of people you wish to study
What is a sample?
A small amount of people taken from the target population
What does it mean if the sample is ‘representative’?
The sample shares the same characteristics as the target population
What does it mean if you can ‘generalise’ the findings?
Apply the result of your study to the target population
Name the four sampling methods
- Random sampling
- Opportunity sampling
- Stratified sampling
- Volunteer sampling
What is random sampling?
Every member of the target population has an equal chance of selection (e.g picking names out of hat)
What is opportunity sampling?
Picking the first available people who fit the target population
What is stratified sampling?
Picking people in proportion to the target population, for example, if it is 60% girls and 40% boys, the sample of 100 should contain 60 girls and 40 boys
What is volunteer sampling?
A technique that asks for participants by placing an advert for volunteers
