Research Methods- Experimental design Flashcards
Experimental design -
The different ways in which the testing of participants can be organised in relation to the experimental conditions.
Independent groups design -
Participants are allocated to different groups where each group represents one experimental condition.
Repeated measures -
All participants take part in all conditions of the experiment.
Matched pairs design -
Pairs of participants are first matched on some variable(s) that may affect the DV.Then one member of the pair is assigned to Condition A and the other to Condition B.
Random allocation -
An attempt to control for participant variables in an independent groups design which ensures that each participant has the same chance of being in one condition as any other.
Counterbalancing -
An attempt to control for the effects of order in a repeated measures design: half the participants experience the conditions in one order, and the other half in the opposite order.
What is experimental design?
Experimental design refers to how participants are arranged and tested in relation to the different experimental conditions.
What is an independent groups design?
An independent groups design involves two separate groups of participants experiencing two different conditions of the experiment, with each participant experiencing only one level of the independent variable (IV).
How is an independent groups design applied in the energy drink study?
One group drinks the energy drink (experimental condition), and a different group drinks water (control condition). The mean number of words spoken by each group is compared.
What is a repeated measures design?
A repeated measures design involves all participants experiencing both conditions of the experiment, with their performance in each condition compared.
How is a repeated measures design applied in the energy drink study?
Each participant first drinks the energy drink (experimental condition) and later drinks water (control condition). The number of words spoken in each condition is compared.
What is a matched pairs design?
A matched pairs design involves pairing participants based on relevant variables (e.g., talkativeness) and assigning one from each pair to different conditions to control for participant variables.
How is a matched pairs design applied in the energy drink study?
Participants are paired based on observed talkativeness, with one from each pair assigned to the energy drink condition and the other to the water condition.
What is the main issue with independent groups designs?
The main issue is that differences in the dependent variable (DV) may be due to individual differences (participant variables) rather than the IV.
How can the issue of participant variables in independent groups designs be addressed?
Researchers use random allocation to distribute participant variables evenly across groups.
What is a disadvantage of independent groups designs in terms of participant numbers?
They are less economical because twice as many participants are needed compared to repeated measures designs to produce equivalent data.
What are the strengths of independent groups designs?
Order effects are not a problem, and participants are less likely to guess the aims of the study.
What is the main issue with repeated measures designs?
Order effects occur because participants experience all conditions, which can affect performance due to practice, fatigue, or boredom.
How can order effects in repeated measures designs be addressed?
Researchers use counterbalancing to ensure participants experience conditions in different orders.
Why are demand characteristics more likely in repeated measures designs?
Participants are more likely to guess the study’s aims because they experience all conditions.
What are the strengths of repeated measures designs?
Participant variables are controlled, and fewer participants are needed compared to independent groups designs.
What are the advantages of matched pairs designs?
Order effects and demand characteristics are less of a problem since participants only experience one condition.
What is a limitation of matched pairs designs?
Participants can never be matched exactly, and matching can be time-consuming and expensive, especially if a pre-test is required.
How does random allocation help in independent groups designs?
It reduces the influence of participant variables by randomly assigning participants to different conditions.
What is counterbalancing, and why is it used in repeated measures designs?
Counterbalancing ensures participants experience conditions in different orders to control for order effects.
Why might matched pairs designs be less economical than other designs?
They require time and resources to match participants effectively, especially if a pre-test is needed.
