Research Methods - Extraneous Variables Flashcards
What are extraneous variables?
Any variable that isnt being investigated that can potentially affect the outcomes of the research study
What are the 2 main sources of extraneous variables?
Participant variables & Situational variables
What are participant variables?
Variables that are connected with the research participant
E.g. gender/age/intelligence
What are situational variables?
Variables that are connected with the research situation
E.g. time of day/temperature/noise
What are participant effects?
When the participants behaves in a way that may bias the validity of the research findings
What are the 4 participant effects?
Participant reactivity
Evaluation Apprehension
Social Desirability bias
The Hawthorne effect
What is participant reactivity?
When behaviours & reactions are impacted by the participant’s knowledge that they are part of a study
What is evaluation apprehension?
When the participant’s behaviour is distorted as they fear being judged by observers/other group members
What is social desirability bias?
Occurs when participants give answers/act in a way that they believe will make them look good to others
What is the Hawthorne effect?
When participants act differently because they become aware that they’re being observed
What are demand characteristics?
When a participant will try an act in a way that they believe aligns with what they guess is expected of them or acting in the opposite of what they think is expected (the ‘screw you’ effect)
What are investigator effects?
When the investigator may bias the results of a study consciously/unconsciously due to
Non verbal communication - e.g. raised eyebrows
Physical characteristics - gender
Bias in the interpretation of data - interpreting the data in a way they see as ‘correct’
What is expectancy bias?
occurs when an individual’s expectations about an outcome influence perceptions of their own/others’ behavior
What are confounding variables?
Factors other than the IV that may cause a result & consequently have an effect on the IV & DV
How do we control extraneous variables?
Use a pilot study
What is a pilot study?
A small scale prototype of a study carried out in advance to the full research
Why is a pilot study carried out?
To find out problems in the experimental design, instructions for participants & measuring instruments
What kind of things do you do in a pilot study?
Give a questionnaire for a small number of people to complete & ask them to rate it an give critisms
What is standardisation?
Where all of the situational variables are kept identical
How might the researchers standardise the experiment?
Keep the experiment at the same time of day, same temperature etc.
What is mundane realism?
To what extent are the experimental findings generalisable to the real world.
A measure of external validity
How might researchers keep mundane realism?
Do a field experiment
What is a single blind technique?
When only the researcher knows the aim of the experiment
How may the researchers do the single blind technique?
Use a placebo which only the researcher knows about
What is the double blind technique?
When the participants & the researcher dont know who is receiving a particular treatment
How might the researcher use the double blind technique?
Using a placebo to test a specific medication
What is randomisation?
When the trials are presented in a random order to avoid any bias the order of the trials may present
