U2: experimental methods and designs Flashcards
Define experimental method
A research approach that involves manipulating an independent variable (IV) to observe its effect on a dependent variable (DV).
Name the 4 experimental methods
Lab
Field
Natural
Quasi
Define lab experiment
Conducted in a controlled environment where the researcher manipulates the IV.
Give an example of a lab environment
lab, classroom, office
Define field experiment
Conducted in a natural setting where the researcher manipulates the IV.
Define natural experiment
The IV is naturally occurring, and the researcher does not manipulate it
Give an example of Natural experiment
anywhere, where the behaviour is natural to that environment i.e., classroom- students learning information
Define Quasi experiment
The IV is a pre-existing characteristic (e.g., age, phobia) that cannot be manipulated
What i meant by ecological validity
The extent to which the results of a study can be generalized to real-life settings.
Which experimental method has high ecological validity
natural
Which experimental method has low ecological validity?
Lab
Define demand characteristics
When participants change their behavior because they are aware of being studied.
Which experimental method are you more likely to have demand characteristics
Lab
Which experimental method are you less likely to have demand characteristics
field and natural
What is meant by experimental designs
Refers to how participants are allocated to different conditions in an experiment.
What is the difference between experimental method and experimental design
Method: Environment
Design: how ppts are allocated
Name the experimental designs
independent groups
repeated measures
What is meant by independent groups design
Participants take part in only one condition of the experiment.
How do you conduct a independent groups design
Recruit participants and split them into equal-sized groups.
Allocate each group to a different condition.
What is a strength of independent groups design
Avoids order effects like practice or fatigue.
What is a weakness of independent groups design
Potential participant differences between groups.
What is meant by repeated measures?
Participants take part in all conditions of the experiment.
How do you conduct a repeated measures design
Participants complete one condition, then after a sufficient time lapse, complete the other condition.
Tasks should differ but be matched in difficulty.
What is a strength of repeated measures?
Controls for participant differences.
What is a weakness of repeated measures?
May lead to order effects
What is meant by order effects
When participants become tired/ bored or get better at the task after doing multiple conditions
what two effects are there in order effects
practice effect
fatigue effect
What is meant by practice effect
Participants improve in the second condition due to familiarity with the task.
what is meant by fatigue effect?
Performance worsens in the second condition due to tiredness.
What is meant by controls in research?
Strategies used to minimize issues with experimental designs and prevent extraneous variables from becoming confounding variables.
By controlling research, how does this improve the study
Increase internal validity.
What two ways can we control research?
Random allocation
Counterbalancing
What is meant by random allocation?
Ensures participants have an equal chance of being in any condition, reducing bias.
How would random allocation be used in research?
Write participant names on equal-sized papers, place them in a hat, and randomly assign them to conditions.
What is meant by counterbalancing?
Reduces order effects by having half the participants complete conditions in one order and the other half in the reverse order.
Does counterbalancing eliminate order effects?
Order effects are distributed rather than eliminated.
