aims, hypothesis, variables

• aim- purpose of an investigation
• hypothesis- prediction of the relationship between two variables
• independent variable- the variable the researcher manipulates
• dependent variable- the measurement taken by the researcher
• extraneous variable- a variable that could affect the results if not controlled
• confounding variable- extraneous variables that were not controlled and did affect the DV
• alternate hypothesis- predicts the IV will have an effect on the DV

  null hypothesis- predicts there is no relationship between the IV and DV
• directional (one-tailed) hypothesis- the researcher predicts a specific direction of the relationship between the variables

  non directional (two-tailed) hypothesis- there will be a difference but no specific direction, when there was no previous research to indicate a direction