Variables

• Variables


  Things that change or vary in the world, some of which may directly cause other changes
• Experiment


  • Researchers attempt to hold most variables the same while manipulating and measuring other variables
• Independent variable


  The variable that the researcher manipulates or changes in an experiment
• Dependent variable


  The variable that the researcher measures for changes in an experiment
• Covariate


  Variables measured in correlational studies to look for relationships
• Extraneous variable


  Any variable other than the independent variable that could influence the measurement of the dependent variable
• Confounding variable


  An extraneous variable that changes systematically with the levels of the independent variable
• Controlling for extraneous variables

  1. Random allocation

  2. Matched pairs design

  3. Counterbalancing

  4. Standardized procedures

  5. Single/double blind trials

  6. Pilot studies

  7. Peer review
• Pilot studies are used to identify and correct extraneous variables before running the full-scale study
• Peer review involves showing the written-up study to other experts to get feedback on potential extraneous variables that may have been missed