Variables

• Which variable does the researcher manipulate or change?

  The independent variable (IV)
• Which variable does the researcher measure?

  The dependent variable
• What are psychologists limited to observing and measuring?

  Their behavior
• What is an operational definition?

  Description of a variable by how it's measured
• Which is a better way to phrase a hypothesis?

  Boys will have a higher teacher rating
• Why do we need to control EVs?

  So they do not affect everyone
• How might a confounding variable differ from an extraneous variable?

  It may affect only some participants
• What are three categories of variables that could affect research measuring students' effort and grades?

  • Situational Variables: Environment factors causing effects.
  • Participant Variables: Differences between people.
  • Investigator effects: Researcher influencing results.
• Which variable changes as a direct result of manipulating the IV?

  The dependent variable (DV)
• Why do psychologists have to work out ways of measuring mental processes?

  We cannot directly see what goes on
• What kind of definitions do psychologists use to describe mental processes?

  Operational definitions
• Why is it important to operationalise variables when writing a hypothesis?

  To clearly define measurement
• What are extraneous variables (EV)?

  Other variables with effect on the DV
• What is a confounding variable?

  A variable affecting the DV if uncontrolled
• What are three categories of variables that could affect research measuring students' effort and grades?

  • Situational Variables: Environment factors causing effects.
  • Participant Variables: Differences between people.
  • Investigator effects: Researcher influencing results.