Psychological investigations Flashcards
Example of an alternate hypothesis? Alcohol and memory.
The amount of alcohol an individual consumes will significantly effect their memory capacity.
What is a null hypothesis?
This predicts the results and researcher obtains will be due to chance
Example of a null hypothesis?
The amount of alcohol an individual consumes will not significantly effect their memory capacity.
What is a one tailed hypothesis?
Predicts the direction of the correlation or difference.
One tailed hypothesis example?
The group consuming alcohol will score significantly lower on a memory recall test.
What is a two tailed hypothesis?
Predicts there will be a significant difference or correlation but doesn’t specify the direction.
Example of a two tailed hypothesis?
There will be a significant difference in the scores on a memory recall tests between participants who have consumed alcohol and participants who haven’t.
What is an independent variable?
A variable manipulated by the experimenter.
What is a dependent variable?
The outcome measured by the experimenter.
What is an extraneous/ confounding variable?
A variable that isn’t the IV which can affect the DV.
What are participant variables?
How are they controlled?
Variables that occur within the individual participant and can effect their performance. E.g. Concentration
Random allocation of participants
What are situational variables?
How are they controlled?
Variable which occur in the experimental environment which could change and effect results, for example the noise levels.
Standardised procedures
Operational definition of a variable?
To operationalise a variable you state specifically how you will measure and manipulate it.
What is an alternate hypothesis?
A prediction in the form of a testable statement.
What is a laboratory experiment?
Where the experimenter can manipulate the IV and there is strict control over extraneous variables.
Strength x2 and weakness x2 of a lab experiments?
- high in reliability.
- cause and effect can be established.
- low in ecological validity.
- cannot be generalised as its artificial
What is a field experiment?
The IV can still be manipulated but in a natural environment.
X2 strengths and x2 weaknesses of field experiments?
- high in ecological validity
- demand characteristics won’t occur
- low in validity, lack of control
- low in reliability, hard to replicate
What is a quasi experiment?
The IV is manipulated by a natural occurrence and not the experimenter and only the DV is measured.
x2 strengths and x2 weaknesses of quasi experiments?
- some ecological validity as a natural occurrence is allowed
- more generalisable
- lacks control so low in validity
- hard to replicate so low in reliability
What is independent measures?
Different participants used for each condition.
X2 strengths and weaknesses of independent measures?
- order effects won’t occur
- demand characteristics controlled
- more participants needed
- participant variables could occur
What is the repeated measures design?
The same participants are used for all conditions.
x2 strengths and weaknesses of repeated measures?
- less participants needed
- no participant variables
- order effects could occur
- demand characteristics could occur
What is the matched pairs design?
Where different participants are used for each condition but matched on certain features.
x2 strengths and weaknesses of matched pairs?
- no participant variables
- no order effects
- more participants needed
- matching participants is very hard and time consuming
