Lab experiment
Conducted in a very controlled environment.
Quasi experiment
Experimenter does not manipulate the IV. The IV is naturally occurring. This may be in a lab or field.
Field experiment
Carried out in someone’s natural environment/ everyday surroundings.
Advantages of a lab experiment
Disadvantages of a lab experiment
- may cause demand characteristics
Advantages of a quasi experiment
- high in ecological validity, looking as ‘real’ problems
Disadvantages of a quasi experiment
Advantages of a field experiment
Disadvantages of a field experiment
Independent measures
Participants allocated to 2+ experimental groups, representing the different levels of the IV.
Advantages of Independent measures
- avoids the aim of the experiment being guessed (DM)
Disadvantages of Independent measures
- more participants are needed
Repeated measures
Participants receive both parts of the IV. There may also be a control condition.
Advantages of Repeated measures
- fewer participants needed
Disadvantages of Repeated measures
- purpose guessed (DM)
Matched pairs design
Participants receive one side of the IV but are matched with someone from the other groups on certain characteristics. Each group Is given one level of the IV.
Advantages of Matched pairs
- avoids order effects
Disadvantages of Matched pairs
- may not control all participant variables
Independent variable
The factor directly manipulated by the experimenter to oversee the effect on the variation of the DV. There are at least two levels of the IV.
Dependent variable
Measured by the experimenter to assess the effects on the IV.
Operationalisation
Defining the IV and DV in a way that they can be measured.
Confounding (extraneous) variables
Factors other than the IV that may cause a result.
Participant variables
A characteristic of the participants such as age or intelligence which could confound results.
Situational variables
A feature of the environment that may affect performance, such as a distracting noise or time of day.