Research methods Flashcards
Aim
A statement of a study’s purpose
When are aims stated?
Before the research begins - to make it clear what the study intends to hypothesis
One-tailed hypothesis
States the direction of a difference or a relationship e.g. more/Less, higher/lower, faster/slower
Examples of one tailed hypothesis
People who drink Red Bull become more hyperactive than people who don’t
When would you use a one-tailed hypothesis?
When pre-existing research supports aim
Two tailed hypothesis
The nature of a difference between conditionals/groups is not specified
Example of two tailed hypothesis
There will be a difference in memory recall for chocolate and no chocolate.
When would you use a two-tailed hypothesis?
When there is no pre-existing research to support an aim
Null hypothesis
When we assume there’s no difference in between variables
Null hypothesis key features
We assume there’s no difference in between variables.
Any data collected will either back this assumption or not: If it doesn’t, you reject it and go with your alternative hypothesis
Example of null hypothesis
No difference on a person’s memory between eating chocolate and not eating chocolate
Operationalisation
How we intend to measure our independent and dependent variables
Extraneous variables
Any variables impacting the dependent variables that aren’t independent variables
Repeated Measures design
There’s only one group of participants. This group takes part in both conditions
When is a repeated measures design used?
Mostly when you have a small number of participants
Advantages of repeated measures design
- No individual differences - the same person does both conditions
- Less participants are needed
Weaknesses of repeated measures design
- Order effects - either boredom, or practice. Can be helped by counter-balancing.
- Demand characteristics - participants know what the experimenters are expecting and may perform to meet that expectation
Independent Groups Design
There are two separate groups of participants. One group takes part in condition A, the other takes part in condition B.
Advantages of experimental design
- No order effects - only take part in one condition - so don’t get bored or practiced
- Fewer demand characteristics - participants may only know their condition
Disadvantages of experimental design
- Individual differences as the people taking part in each condition are different - one group might simply be better at that task.
- More participants are needed
Matched pairs
There are two separate groups, but this time they’re matched into pairs for certain qualities, such as age or intelligence. One of each pair takes part in condition A, the other takes part in condition B.
Matched pairs design advantages
- No order effects
- Controls for individual differences - can be more sure the IV caused differences in DV rather than big differences between the 2 groups
Matched pairs design disadvantages
Can be difficult to make perfect matches and is costly on money and time
Counterbalancing
Half of the participants participate in Condition A before condition B and vice versa - the first and second condition is not the same for every participant
Randomisation
Materials presented in a random order to avoid order effects
Random allocation
An attempt to control for participant variables in an independent groups design which ensures each participant has the same chance of being in one condition as any other.
Standardisation
Using exactly the same formalised procedures and instructions for all participants in a research study
Disadvantages of Hawthorne effect
Results are artificially high: invalid conclusions
If participants are uninterested - opposite occurs(screw you)
Laboratory experiment nature and use
Controlled artificial environment
Independent variable is manipulated
Lab experiment advantages
- Controlled environment:
- Minimises problems with extraneous variables:
- High internal validity
Lab experiment disadvantages
- Artificial environment(low mundane realism)
- Demand characteristics - participant behaves differently to normal or may be affected by the environment
- Low external validity - lack of generalisability
Field experiment nature and use
These take place outside of the lab, in a natural environment, but the basic scientific procedures are still followed as far as possible.
The independent variable is manipulated
The effect of the dependent variable is measured.
Example of a field experiment you’ve studied
Bushman/Bickman
Field experiments advantages
Less artificial than a lab, but still an experiment(mundane realism)
Avoids participant effects(if not aware of study), therefore it should produce behaviour which is more natural and valid, less demand characteristics
Field experiment weaknesses
Extraneous variables are less easy to control, therefore less able to show cause and effect:
Ethical issues - participants unlikely to know they’re being studied
Natural experiment nature and use
Natural environment: Independent variable not manipulated taking advantage of a naturally occurring event
Natural experiment advantages
High ecological validity - opportunities for research which otherwise might not be available
Enables psychologists to study real problems
Few ethical issues
Natural experiments weaknesses
A naturally occurring event may happen very rarely
Many extraneous variables which are a threat to ‘cause-effect’ conclusion
Some bias - participants not randomly allocated to conditions
Quasi experiment nature and use
In quasi experiments, the IV is a naturally existing characteristic(e.g. biological sex, eye colour) between people, and has not been changed by anyone or anything.
Quasi experiment advantages
Often carried out under laboratory conditions, so therefore high in controls: enables psychologists to study ‘real’ problems
Disadvantages of quasi experiments
Like natural experiments, participants cannot be randomly allocated to conditions, therefore they may be confounding variables:
This means we cannot establish cause and effect
