What is the difference between an aim and a hypothesis?
What is the experimental method?
While all other variables are held constant, one variable is manipulated (IV) and the effect of this on another variable is measured (DV)
What is the difference between a directional and non-directional hypothesis?
What is a natural experiment?
A natural experiment is an experiment in which the IV is not brought about by the researcher hence would have happened even if the researcher had not been there e.g. if studying reactions to earthquakes
What are the limitations of a natural experiment? (A03)
What are true experiments?
True experiments control the variables under investigation, and randomly allocate participants to groups
Lab and field experiments are both true experiments
What is an extraneous variable?
An extraneous variable is any variable that you’re not investigating that can potentially affect the outcomes of your research study
Doesn’t vary systematically with the IV - nuisance variables
What is a confounding variable?
A confounding variable is a variable other than the independent variable that systematically affects the dependent variable
Difficult for the researcher to be sure of the origin of the impact of the DV as the confounding variable could have been the cause
What is the difference between randomisation and standardisation?
What is operationalisation?
Making sure your variables are in a form that can be easily tested
What are the strengths of a natural experiment? (A03)
+ Provides opportunities: for research that would have otherwise been impossible due to practical/ethical reasons
+ High external validity: dealing with real-life issues
What are the 4 types of experiments?
Laboratory, field, natural, quasi
What is a lab experiment?
A lab experiment is an experiment that takes place in a special environment whereby different variables can be carefully controlled
What are demand characteristics?
Aspects of the study which lead participants to guess the aim of the study and form expectations about how they should behave
What are the 3 types of experimental design?
Independent groups
Repeated measures
Matched pairs
What is a field experiment?
A field experiment is an experiment conducted in a more natural environment, not in a lab but with variables still being well controlled
What are the strengths and weaknesses of a field experiment?
Strengths:
- Naturalistic: so more natural behaviours hence high ecological validity
- Controlled IV
Limitations:
- Ethical considerations: invasion of privacy and likely to be no informed consent
- Loss of control: due to extraneous variables hence precise replication not possible
What is independent groups design?
Two different groups experience two different conditions - the IV is naturally occurring
What is a strength and weakness of quasi experiments? (A03)
+ Controlled conditions: hence replicable, likely to have high internal validity
- Cannot randomly allocate participants: may be confounding variables presented - makes it harder to conclude that the IV caused the DV
What are the weakness of lab experiments? (A03)
What is the difference between external validity and internal validity?
What is a quasi experiment?
What are the strengths of a lab experiment? (A03)
+ High degree of control: all variables are controlled, IV has been precisely replicated - greater accuracy
+ Replication: researchers can repeat experiments and check results
What are the strengths of independent groups design?
+ Order effects can’t be observed as no participants are used in more than one condition
+ Data collection is less time-consuming - all conditions of the experiment can be conducted simultaneously