What is a lab experiment?
an experiment carried out in a controlled environment
What are the advantages to a lab experiment?
- high levels of control
- ability to replicate the study
- manipulation of IV indicates cause and effect
What are the disadvantages to a lab experiment?
- lacks ecological validity
- results more likely to be biased by sampling
- demand characteristics
What is a field experiment?
an experiment carried out in a natural setting
What are the advantages to a field experiment?
- high in ecological validity
- natural, less bias from sampling
- no demand characteristics
What are the disadvantages to a field experiment?
- low amounts of control
- more biased from extraneous variables
- difficult to replicate
- ethical issues
What is a natural experiment?
an experiment where the researcher does not manipulate the IV.
What are the advantages to a natural experiment?
- greater ecological validity (IV isn’t changed directly)
- little bias from sampling
- no demand characteristics
- can study ‘real’ problems
What are the disadvantages to a natural experiment?
- no randomly allocation
- event is a ‘one-off’, reducing opportunity for research
What is a Quasi experiment?
an experiment where the IV is based on a pre-existing difference between people (i.e. age or gender). Nobody has manipulated this IV, it simply exists
What are the advantages to a Quasi experiment?
- high amounts of control
- comparisons can be made between people
What are the disadvantages to a Quasi experiment?
- no random allocation as IV pre-exists
- casual relationships not demonstrated, we cannot say for certain that a change in the DV was due to the IV
- ethical issues
What are the 2 types of demand characteristics?
‘Screw you’ effect
‘Social desire-ability’ effect
What are some ethical problems?
Consent
Deception
Confidentiality
Protection from harm
Withdrawal
Debriefing
What are the types of consent?
Retrospective - doing the research before, then asking if they would like their data withdrawn
Presumptive - asking a group of similar people about how they would feel about taking part in that research
Informed - written, recorded or verbal consent from participant
