Research MethodsResearch MethodsIndependent & Dependent Independent & Dependent

VariablesVariables

IndependentIndependent VariablesVariables

• The independent variable is the thing The independent variable is the thing the psychologist changes or the psychologist changes or manipulates when conducting an manipulates when conducting an experiment. experiment.

• This is to try and discover a cause-This is to try and discover a cause-effect relationship between the IV effect relationship between the IV and the dependent variable.and the dependent variable.

Example…Example…

An example of an independent variable:An example of an independent variable:

•whether participants in a whether participants in a memory experiment were memory experiment were asked to make a story out of asked to make a story out of a list of words (to help them a list of words (to help them memorise the words) or memorise the words) or given no instructions on how given no instructions on how to memorise the wordsto memorise the words

Dependent VariablesDependent Variables

• The name given to the variable in The name given to the variable in experimental research that experimental research that measures/ observes any change in measures/ observes any change in animal or human behaviours as a animal or human behaviours as a result of their exposure to the result of their exposure to the independent variable. independent variable.

• As a consequence we can discover if As a consequence we can discover if the change or manipulation of an the change or manipulation of an independent variable has caused, or independent variable has caused, or had an effect on how we think, feel, had an effect on how we think, feel, or behave; this change being or behave; this change being measured measured as the dependent as the dependent variablevariable

Example…Example…

The dependent variable for a memory The dependent variable for a memory experiment could be:experiment could be:

•The number of words The number of words recalledrecalled

Test…Test…• You must decide which of the following You must decide which of the following

are IVs or DVs…are IVs or DVs…

1.1. Giving ppts either alcohol or juiceGiving ppts either alcohol or juice2.2. Ppts ability to drive safelyPpts ability to drive safely3.3. Whether ppts memorised words at the Whether ppts memorised words at the

bottom of the ocean or on the beachbottom of the ocean or on the beach4.4. The number of anagrams solved in 2 The number of anagrams solved in 2

minutesminutes5.5. The attention span of a gold fishThe attention span of a gold fish6.6. The time of dayThe time of day

Now you need to have a Now you need to have a go…go…

• See IV – DV activities in the Science See IV – DV activities in the Science Pack Pack