Types of experiments Flashcards
What are the 4 types of experiments?
Lab, field, natural and quasi
What is a lab experiment?
The aim of a lab experiment is to try and control all of the variables apart from one key variable which is known as the independent variable. The experiments are conducted in a artificial setting.
What are the strengths of a lab experiment?
The effects that confounding variables have are minimised.
Strict control means that the study can be replicated.
It makes it easy to spot a relationship between variables
What are the weaknesses of a lab experiment?
As they occur in artificial settings the results may lack ecological validity.
Demand characteristics- participants may respond in an un-natural way leading to bias results
Ethics- deception is often used making informed consent difficult
What is a field experiment?
Experiments conducted outside the lab where behaviour is measured in a natural environment e.g. a school or a train. The independent variable is still manipulated.
What are the strengths of a field experiment?
You can still establish a casual relationship by manipulating the independent variable and measuring its effect
They have a high ecological validity as they relate to real life
Demand characteristics can be avoided if people are not aware that they are being studied
What are demand characteristics?
Participants trying to guess what the researcher expects from them and performs differently because of it
What are the weaknesses of field experiments?
Confounding variables are harder to control and are therefore more likely
Ethics- participants who don’t give consent for the experiment might experience stress and often can’t be debriefed. Observation must respect privacy.
What is a natural experiment?
Where a researcher looks at how the independent variable which isn’t manipulated affects the dependant variable. The IV isn’t manipulated because it is an event which occurs naturally e.g. looking at behaviour in a single sex and mixed set school
What type of sampling is used for natural experiments?
Random
What are the strengths of natural experiments?
It is possible to study variables that would be unethical to manipulate
Less likely to have demand characteristics
High ecological validity
What are the weaknesses of natural experiments?
Because the IV is not manipulated it is hard to establish a casual relationship
Ethics- deception is often used making informed consent difficult
What is a quasi experiment?
The researcher cannot use random allocation. This is because the IV is specific to a person e.g gender and mental disorder
What are the strengths of quasi experiments?
They are often carried out under controlled conditions.
It is likely you will be to generalise these results to real life
What are the weaknesses of quasi experiments?
Confounding variables are likely to occur
It can be hard to establish a casual relationship
