variables Flashcards
what is the independent variable?
variable changed/manipulated by researcher
what is the dependant variable?
variable measured by researcher
what is the only thing that should influence the dependant variable?
the independant variable
what is operationalisation?
clearly defining variables in terms of how they are measured
what is an extraneous variable?
any other variables apart from independent variables that have an affect on dependant variable, if not controlled by experimenter
what happens if you don’t control extraneous variables?
they become confounding variables meaning we cannot establish cause and effect
what are the types of extraneous variables?
● participant variables
● situational variables
● investigator effects
what are participant variables?
individual differences between participants that could affect dependant variable
what are examples of participant variables?
● personality
● age
● gender
● motivation
● intelligence
● concentration
what are situational variables?
features of experimental situation / environment that could affect dependant variable
what are examples of situational variables?
● noise
● time of day
● weather
● temperature
what are investigator effects?
any unwanted influence of investigator on research outcome
what are examples of investigator effects?
if investigator is very helpful to one group and not helpful to the other (may do this to create particular results)
what are demand characteristics?
● participants change their behaviour as a result of being in experimental situation
● might deliberately under preform / act in a way they think is expected and over preform
● behaviour is no longer natural and acts as an extraneous variable
what are 3 examples of how to control extraneous variables?
● random allocation
● standardisation
● double blind procedure
what is random allocation?
● participants randomly allocated to each condition of the independent variable
● attempts to evenly distribute participant variables across conditions of experiment
what does random allocation control for?
participant variables
what is standardisation?
using the exact same formalised procedures and instructions for all participants in a research study
what does standardisation control for?
investigator effects, situational variables
what is a double blind procedure?
neither participants nor researcher who conducts study is aware of aims of investigation
what does a double blind procedure control for?
● demand characteristics
● investigator effects
what are order effects?
● order of conditions affecting participants behaviour
● e.g. performance in second condition better due to participants knowing what to do
performance might be worse in second condition as they are tired
what is counter balancing?
● half of the participants complete condition 1 first
and condition 2 second
●other half of participants complete condition 2 first and condition 1 second
● doesn’t get rid of order effects
but stops order from becoming confounding variable as effect is balanced out over two conditions
