Independent and Dependent Variable
An independent variable is one that is intentionally changed, during the experiment, to observe its effect on the dependent variable.
The dependent variable is what will be measured during the experiment. It is what the experimenter thinks will be affected by the independent variable during the experiment.
For example, we might change the type of information (e.g. organized or random) given to participants to see what affect this might have on the amount of information remembered.
In this particular example the type of information is the independent variable (because it what changes) and the amount of information remembered is the dependent variable (because this is what is being measured).
Learning Activity 2.4
1. IVs – Listening to different sports broadcasts or not, test being studied
DV – The test results
2. IVs – Having different mindsets (positive/negative)
DV – Percentage of goals shot
3. IVs – Smoking or not smoking, driving conditions and locations
DV – Reaction time/other measure for driver alertness
4. IVs – Size of crowd/amount of people surrounding experiment’s subjects
DV – Behaviours
5. IVs – Different visual and sound stimuli
DV – Reaction time
6. IVs – Different simple tasks and complex tasks
DV – Amount of concentration shown (amount of daydreaming)
7. IVs – Amount of marijuana smoked/consumed, different memory tasks
DV – Performance on memory tasks
8. IVs – Amount of red cordial drank
DV – Measurement of hyperactivity (observation, heart bpm, etc.)
9. IVs –Amount of stress that the person has (determined by questionnaire/test)
DV – Stomach health (whether there are/aren’t stomach ulcers)
10. IVs – Different times of day/night, different people (male/female, young/old, etc.)
DV – Brain wave activity
Learning Activity 2.5
1) A) An extraneous variable is a variable that may influence the outcome of an experiment but is not manipulated by...