What are lab experiment ?
High level of control the researcher has over all the variables in the study
Uses standardised procedures
Indepedant variable is changed
What are strengths of lab experiments?
-can establish a cause and effect relationship
-high internal validity
-easily replicated due to standardised procedures
What are weakensses of lab experiments?
-lack ecological validity
-lack mundane realism lowering the external validity
-ppts are aware they’re being tested so demand characteristics might affect results
What is a field experiment?
Conducting the experiment in naturalistic settings
Independent variable is still changed
What are the strengths of field experiments?
-high ecological validity as ppl behave naturally
-have mundane realism
-don’t show demand characteristics
What is a weakness of field experiments?
-lack control over extraneous variables that could be influencing the measurement of the dependant variable
-difficult to randomly assign resulting in a change in DV might be due to participant variables reducing internal validity
What are natural experiment ?
Two levels of independent variables have occurred naturally without the influence of the researcher the researcher simply records the change in the dependant variable between the two levels of IV
What are strengths of natural experiments?
-allow research to happen in areas that couldn’t happen in controlled experiments
-hihg in external validity
What are weaknesses of natural experiments?
-can’t find a cause and effect relationship due to not being able to control extraneous variables
-can’t be replicated so low reliability
What is a quasi experiment?
An experiment whereby the iV hasn’t been determined by the researcher instead it naturally exists e.g. gender difference studies
What are strengths of quasi experiments?
Controlled conditions- replicable, high internal validity
What are weaknesses of quasi experiments ?
Can’t randomly allocate so can’t establish cause and effect
What are aims?
General statement made by the researchers which tells us the purpose of their study
What is a hypotheses?
Precise statement which clearly states the relationship between the variables being investigated
What’s the difference between a directional and non directional hypotheses?
Directional states the direction of the relationship that will be shown between the variables
No directional doesn’t
E.g directional- the more sleep a ppts has the better the memory performance
Non directional-the difference between the hours of sleep will have an effect on memory performance
Directional is usually used when there has been previous research done on this topic
What is the indepednat variable ?
Aspects of the environment which has been manipulated by the researcher to have an effect on the DV which is then measured
What is the dependant variable?
Measured by the researcher and has caused a change to the IV
What is operationalisation?
Act of a researcher clearly defining the variables in terms of how they are being measured
What is an extraneous variable?
Any other variable which isn’t the IV that affects the DV and doesn’t vary systematically with the IV
What is a confounding variable?
A variable other than the IV which has an effect on the DV and does change systematically with the IV
E.g. time of day those who do the memory test later in the day may be more tried
What are demand characteristics ?
Any cue the researchers or the research situation may give which makes the ppt feel like they can guess the aim of their investigation
What is the investigator effect?
Any unwanted influence from the researchers behaviour on the DV measured
E.g design of study of selection of ppts
What is randomisation?
The use of chance to reduce the effects of bias from investigators effect
What is standardisation?
Using the exact same formalised procedures and instructions for every single ppts involved in the research process