purpose of statistical testing

• What can cause differences between two groups or sets of results?

  Chance can cause differences between them
• What is needed to calculate the probability that chance caused a difference?

  A statistical test
• Why do psychologists use statistical tests?

  To conclude significant differences exist
• What does a significant difference indicate in an experiment?

  The change in IV caused change in DV
• Why is using statistical tests crucial in the scientific method?

  They validate findings and support conclusions