Booklet 1: Experiments Flashcards
(23 cards)
What is the independent variable (IV)?
The variable that is changed or manipulated by the researcher to see if it has an effect on the DV (1)
What is the dependent variable (DV)?
The variable that the researcher measures to see the effect on the IV (1)
What is the aim?
A general statement of what the researcher intends to investigate, the purpose of the study
What is the hypothesis?
A specific, testable statement in which the researcher predicts what will happen between the variables
What is a directional hypothesis?
The researcher predicts the direction that they think the results will go in
How do you write a directional hypothesis?
There will be a significantly higher/faster/more (operationalised DV) when participants (one condition of IV) compared to when participants (other condition of IV)
What is a non-directional hypothesis?
The researcher does not predict the direction that they think the results will go in. They will just say that there will be a difference.
How do you write a non-directional hypothesis?
There will be a significant difference in (operationalised DV) when participants (one condition of IV) compared to when participants (other condition of IV)
What is a null hypothesis?
States that the results gain were due to chance and not the independent variable that the researcher changed/manipulated
When would you use a directional hypothesis?
“All past research has shown…”
“Previous research has shown…”
When would you use a non-directional hypothesis?
New area of research
Limited previous research
Previous research findings have been mixed (“some research has found…”)
What are extraneous variables?
Unwanted, extra variables other than the IV (1) that could have an effect on the DV, this would lower the internal validity of the study (1)
What are the 3 main causes of extraneous variables? (NOT NAMED ON SPEC)
Situational factors (things to do with environment)
Participant variables (things to do with ppts)
Experimenter variables (things to do with researcher)
What are confounding variables?
Extraneous variables that are not controlled for so DO have an effect on the DV.
What are the experimental methods?
Lab
Field
Natural
Quasi
What is a lab experiment?
An experiment conducted in a lab which is a highly controlled environment (1)
Where the researcher manipulates the IV and measures the effect on the DV (1)
What is a Field experiment?
An experiment which takes place in a natural environment (for the ppts) (1)
Where the researcher manipulates the IV and measures the effect on the DV (1)
What is a natural experiment?
The researcher takes advantage of a naturally occurring IV (event)
The variable would have changed even if the experimenter was not interested
(note: it is the IV that is natural, not the setting)
What is a quasi experiment?
An experiment which has an IV based on an existing individual difference between people (characteristic) (1)
which the researcher has not manipulated e.g. age or gender (1)
and the researcher measures the effect on the DV
What are the strengths of a lab experiment?
High level of control over extraneous variables -
Carried out in fake environment (CONTEXT)
Cause and effect can be established between IV and DV
Increases internal validity
High in reliability -
experiment (CONTEXT) can be easily repeated in same conditions
to check for consistent results
What are the limitations of a lab experiment?
Lacks ecological validity -
Carried out in artificial environment (CONTEXT)
Difficult to generalise findings (CONTEXT) beyond setting of study
Lowers external validity
Prone to demand characteristics -
Ppts change their natural behaviour based off clues given off by the researcher (CONTEXT)
Could lead to ppts choosing to help or hinder the researcher
Reducing the internal validity
What are the strengths of a field experiment?
Less prone to demand characteristics -
People might not know they’re being watched
Less likely to guess clues given off by researcher and change their natural behaviour (CONTEXT)
Increasing internal validity
High ecological validity -
Based in a real life setting
Easier to generalise the findings beyond the setting of the study to other similar settings (CONTEXT)
Increasing the internal validity
What are the limitations of a field experiment?
Low in reliability -
Environment is natural (CONTEXT)
Difficult to repeat with exactly the same conditions to check for consistent results
Lack of informed consent -
Could create ethical issues
People may not be aware they are being studied (CONTEXT)
So wouldn’t have given their consent
If they become aware they may become upset and wish to withdraw their data from their research
