Please write a paragraph responding to the discussion bellow. Add citations and references in alphabetical order.
The independent variable is the variable the experimenter manipulates (i.e. changes) assumed to have a direct effect on the dependent variable.
The dependent variable is the variable the experimenter measures in their experiment.
Extraneous variables are unwanted factors in a study that, if not accounted for, could negatively affect (i.e. confound) the data subsequently collected. The researcher wants to make sure that it is the manipulation of the independent variable that has changed the changes in the dependent variable. Hence, all the other variables that could affect the DV to change must be controlled. These other variables are called extraneous or confounding variables.
Such factors potentially prevent researchers from finding a direct causal effect between the manipulated independent variables (IVs) and measured dependent variables (DVs) set out in an investigation.
For researchers to be confident that change in the IV will solely affect change in the DV, potential confounds need to be identified and controlled/eliminated; poor control will lead to results with lower reliability.
There are three key considerations to take when controlling extraneous variables:
Participant variables: minimizing differences between participants (e.g. their stage of development such as age, or ability such as IQ).
Researcher variables: factors such as researcher behavior, appearance or gender could affect participant responses, so should be made consistent throughout the experiment.
Situational variables: control of the setting where the experiment takes place, such as keeping light, sound and temperature levels consistent.