Research Methods - controlling variables Flashcards
What is the relationship between control and experimental realism?
Lab experiments have the highest control over extraneous variables but the least realism
High control means an established cause and effect relationship (causality) so high internal validity but low realism means you won’t be able to generalise results to real situations and environments
What is a cyclical process in research?
We see the results in a lab experiment (highly controlled) and then test them in the real world to establish causality
What is mundane realism? What type of validity does it threaten?
Extent to which task is representative of something ppt. would do in their everyday life
Threatens ecological validity
What is experimental realism? What type of validity does it threaten?
Whether experiment has psychological impact and ‘feels real’ to a ppt.
Threatens internal validity
What are extraneous variables?
May affect the DV but you aren’t intentionally studying them - researchers should identify and control for them as they could affect the DV
What are confounding variables?
Variables apart from the IV that have affected the DV
What are uncontrolled variables?
Variables that cannot be controlled
What is a situational confounding/extraneous variable?
Features of the experimental situation (weather, time of day, temp)
What is a participant confounding/extraneous variable?
To do with differences between ppts. (mood, age, gender)
What are other types of extraneous variable?
Researcher bias, demand characteristics and order effects
What are demand characteristics?
Ppts. use cues from the environment to work out aim of study and then their behaviour changes
- “Please you” effect where ppts. try to do what is expected of them
- “Screw you” effect where ppts. try to do the opposite of what is expected of them
What are investigator effects/researcher bias?
Researcher consciously/subconsciously acts in a way to support their prediction (body language, how they’re dressed and can lead to demand characteristics)
What is random allocation? What EV does it help to control?
Each ppt. has same opportunity to be assigned to any given group so individual differences are less likely to affect results
Controls ppt. extraneous variables
What is a standardised procedure? What EV does it help to control?
Procedure is same for each ppt. so it isn’t procedure affecting results but only the IV
Controls for situational extraneous variables
What is randomisation? What EV does it help to control?
Presenting stimuli in a random manner to avoid it having an effect on the DV (randomly choosing the order of words)
Controls for situational extraneous variables
What is a single blind test? What EV does it help to control?
Ppts. don’t know which condition of a study they’re in
Controls for demand characteristics
What is a double blind test? What EV does it help to control?
Neither researcher nor ppt. know which condition each ppt. is in
Controls for researcher bias
