AS & A2 Research Methods
Types of Experiments
Laboratory Field
• Conducted in high controlled • Carried out in natural environments
environments • The IV in manipulated by the
• Participants are generally randomly experimenter just like the laboratory
allocated to the different conditions experiment
• Some situational variables are controlled
Strengths Strengths
• High degree of control over the variables • Natural environment – findings likely to
– cause and effect relationship between represent what you would usually find in
IV and DV a real-life setting (ecological validity)
• Much easier to replicate the findings as • Low demand characteristics
all the other variables can be kept the
same
Limitations Limitations
• High degree of control – artificial settings • Natural environment – lower degree of
• Demand characteristics – may not control over variables – can’t control
represent behaviour in a real-life setting extraneous variables (reduces the internal
as they are likely to know that they are validity)
taking part in an experiment • Hard to replicate study (can’t control the
variables)
Natural Quasi
• Carried out in a naturally occurring • IV that is based on existing differences
environment between people (e.g. gender, age etc).
• The experimenter does not directly • Nobody has manipulated this variable, it
manipulate the IV simply exists.
• Researcher takes advantage of a pre-
existing independent variable
• IV that is natural NOT the setting
Strengths Strengths
• Natural environment – findings likely to • Natural environment – findings likely to
represent what you would usually find in represent what you would usually find in
a real-life setting (ecological validity) a real-life setting (ecological validity)
• Low demand characteristics • Low demand characteristics
Limitations Limitations
• Natural environment – lower degree of • Natural environment – lower degree of
control over variables – can’t control control over variables – can’t control
extraneous variables (reduces the extraneous variables (reduces the internal
internal validity) validity)
• Hard to replicate study (can’t control the • Hard to replicate study (can’t control the
variables)/ unlikely the situation will be variables)/ unlikely the situation will be
exactly the same again exactly the same again
Types of Experiments
Laboratory Field
• Conducted in high controlled • Carried out in natural environments
environments • The IV in manipulated by the
• Participants are generally randomly experimenter just like the laboratory
allocated to the different conditions experiment
• Some situational variables are controlled
Strengths Strengths
• High degree of control over the variables • Natural environment – findings likely to
– cause and effect relationship between represent what you would usually find in
IV and DV a real-life setting (ecological validity)
• Much easier to replicate the findings as • Low demand characteristics
all the other variables can be kept the
same
Limitations Limitations
• High degree of control – artificial settings • Natural environment – lower degree of
• Demand characteristics – may not control over variables – can’t control
represent behaviour in a real-life setting extraneous variables (reduces the internal
as they are likely to know that they are validity)
taking part in an experiment • Hard to replicate study (can’t control the
variables)
Natural Quasi
• Carried out in a naturally occurring • IV that is based on existing differences
environment between people (e.g. gender, age etc).
• The experimenter does not directly • Nobody has manipulated this variable, it
manipulate the IV simply exists.
• Researcher takes advantage of a pre-
existing independent variable
• IV that is natural NOT the setting
Strengths Strengths
• Natural environment – findings likely to • Natural environment – findings likely to
represent what you would usually find in represent what you would usually find in
a real-life setting (ecological validity) a real-life setting (ecological validity)
• Low demand characteristics • Low demand characteristics
Limitations Limitations
• Natural environment – lower degree of • Natural environment – lower degree of
control over variables – can’t control control over variables – can’t control
extraneous variables (reduces the extraneous variables (reduces the internal
internal validity) validity)
• Hard to replicate study (can’t control the • Hard to replicate study (can’t control the
variables)/ unlikely the situation will be variables)/ unlikely the situation will be
exactly the same again exactly the same again
