Experimental Designs Flashcards
What are the three types of experimental designs?
- Repeated measures
- Independent groups
- Matched pairs
These designs differ in how participants are organized in relation to the experimental conditions.
Define experimental design.
The different ways in which participants can be organised in relation to the experimental conditions.
It refers to the structure of an experiment and how participants are assigned to different conditions.
What is an independent groups design?
Participants are allocated to different groups where each group represents one experimental condition.
This design ensures that each participant experiences only one level of the independent variable.
How does a repeated measures design work?
All participants take part in all conditions of the experiment.
This means each participant experiences both conditions, allowing for direct comparison.
Explain matched pairs design.
Pairs of participants are matched on variables that may affect the dependent variable, then assigned to different conditions.
This approach controls for participant variables by ensuring that pairs are similar.
What is random allocation in an experimental design?
An attempt to control for participant variables which ensures that each participant has the same chance of being in one condition as any other.
This method helps to minimize bias in assigning participants to conditions.
Define counterbalancing.
An attempt to control for the effects of order in a repeated measures design by varying the order of conditions.
Half the participants experience the conditions in one order, while the other half experience them in the opposite order.
True or False: In an independent groups design, all participants experience both conditions.
False
In an independent groups design, different participants are assigned to different conditions.
Fill in the blank: In a matched pairs design, participants are paired based on _______.
[key variable(s)]
Variables can include characteristics like IQ, age, or other factors relevant to the study.
What is the main purpose of using a comparison condition in an experiment?
To determine whether the independent variable affects the dependent variable.
A comparison condition allows researchers to assess changes attributable to the independent variable.
What is the primary limitation of the independent groups design?
Participant variables may differ between groups, affecting results.
This design does not control for individual differences as effectively as repeated measures or matched pairs.
What is the role of a pre-test in matched pairs design?
To effectively match participants on relevant variables before assigning them to conditions.
A pre-test helps to identify pairs that are similar on the variable of interest.
Limitations: Independent groups
- Participants variables: individual differences in people can confound the result. (Researchers use random allocation to deal with this)
- More people needed = more expensive
Strengths: Independent groups
- Participants can be randomly allocated to reduce participant variable
- There are no order effect, each group does one condition
- Less time consuming - both conditions can be simultaneous.
Limitations: Repeated measures
- Order effects: repeating two tasks could create boredom or fatigue or alternatively, participants’ performance may improve through the effects of practice.
- Demand characteristics: It is more likely that participants will work out the aim of the study when they experience all conditions of the experiment.
