Experiments Flashcards
Research Methods
Define independent variable.
The variable that the researcher wants to change to see what effect it has on something else.
Define dependent variable.
The variable that is going to be measured and affected by the independent variable.
Define extraneous variables.
A factor that may influence the results so it’s controlled to minimise it’s effect.
Define confounding variables.
A variable that you cannot control that could affect the results.
Define laboratory experiment.
When the independent variable has been manipulated and the experiment is conducted in a controlled/ artificial environment, and the dependent variable is measured.
What are the strengths of a laboratory experiment?
- High internal validity
- High levels of reliability because you can repeat the study to check for consistencies.
What does internal validity mean?
If the study is controlled, and if you can establish a cause and effect.
What does ecological validity mean?
When the study accurately represents a normal daily activity/ daily life.
What are the weaknesses of a laboratory experiment?
- Low ecological validity because they are conducted in artificial environments.
Define field experiment.
When the independent variable has been manipulated, the experiment is in a natural environment, and the dependent variable is measured.
What are the strengths of a field experiment?
- Have high levels of ecological validity.
What are the weaknesses of a field experiment?
- Low levels of reliability because it is difficult to repeat.
- Low internal validity.
Define quasi experiment.
When the independent variable is naturally occurring and has not been manipulated by the researcher.
What are the strengths of a quasi experiment?
- Allows you to look at variables it would be impossible or unethical to investigate otherwise.
- Can be carried out in a lab or natural environment.
What are the weaknesses of a quasi experiment?
- Difficult to establish cause and effect because the independent variable was not manipulated.
- Sampling bias could occur as the researcher does have control over who participates.
Define independent measures design.
When participants complete one condition in the experiment.
What are the strengths of independent measures design.
- No chance of order effects.
- Less chance of demand characteristics.
What are the weaknesses of independent measures design?
- Individual differences.
- Researcher needs more participants.
Define order effects
When one condition or task affects the next condition or task in a study.
Define repeated measures design.
When the participants complete all of the conditions of the experiment.
What are the strengths of repeated measures design?
- No individual differences.
- Don’t need as many participants.
What are the weaknesses of repeated measures design?
- More chance of demand characteristics.
- Higher risk of order effects.
Define matched pairs design.
When participants only complete one condition but they are matched based on certain characteristics to others carrying out the other conditions (age, IQ, gender).
What are the strengths of matched pairs design?
- No order effects.
- Individual differences are reduced.
- Less chance of demand characteristics.
What are the weaknesses of matched pairs design?
- There are still individual differences despite them being reduced.
- Researcher needs more participants.
Define counter balancing.
Ways to solve order effects.
Define hypothesis.
A scientific prediction of what you think is going to happen in the study/ experiment.
Give the sentence you should use when making an alternate hypothesis.
There will be a significant relationship/ difference between ‘condition 1’ and ‘condition 2’ …
Give the sentence you should use when making a null hypothesis.
There will be no significant relationship/ difference between ‘condition 1’ and ‘condition 2’…
What is a one-tailed/ directional hypothesis?
These state the direction of the experiment/ what will happen.
What is a two-tailed/ non-directional hypothesis?
These don’t specify the direction/ what will happen.
Define operationalism.
Clearly defining what is meant by the independent and dependent variables and making them measurable.
