Probability & significance

• What is a Type I error?

  When the null hypothesis is rejected and the alternative hypothesis is accepted, when it should have been the other way around
• What is a Type I error also known as?


  A false positive
• What is a Type II error?

  When the null hypothesis is accepted but it should have been the alternative hypothesis
• What is a Type II error also known as?

  A false negative
• When are we more likely to make a Type I error?

  If the significance level is too lenient (high)
• When are we more likely to make a Type II error?

  If the significance level is too stringent (low)
• What is the standard level of significance in psychology?


  0.05
• When might we use a more stringent level of significance than 0.05?

  In studies with human cost
• What will happen if there is large different between calculated and critical values?

  Researcher will check more stringent levels
• What are the three criteria to know which critical value to use?

  1 ) One-tailed or two-tailed

  2 ) Number of participants (Appears as N or df)

  3 ) Levels of significance
• What do we get once a statistical test has been calculated?

  Calculated value
• How do we check for statistical significance?

  Calculated value must be compared with a critical value
• What does the null hypothesis state?

  There's no difference between conditions
• What does the alternative hypothesis state?

  There is a difference between conditions
• What is probability?


  The likelihood events will occur