Variables

• Independent variable


  A variable whose value does not depend on another variable and can be manipulated to affect the DV in different ways
• Dependent variable 


  A variable whose value depends on another variable and is measured at the end of the experiment
• Co-variables


  Two variables that are both measured in an experiment to see if a correlation exists between them
• Extraneous variable


  A factor whose tendency to change might impact on the DV if it is not controlled in an experiment
• Confounding variable


  An extraneous variable that was not controlled in an experiment and now causes uncertainty about how far the impact on the DV was actually caused by the IV
• Controlled variable


  An extraneous variable that could have impacted the DV but didn't because measures were put in place to standardise it throughout all conditions in the experiment