Probability & Significance

• Can researchers be 100% certain of statistical significance?

  No, they can never be 100% certain
• What is the maximum percentage that the wrong hypothesis can be accepted?

  Up to 5%
• What are the two types of errors in hypothesis testing?

  • Type I Error
  • Type II Error
• What is another name for a Type I error?

  False Positive
• What does a Type I error involve?

  Rejecting the null hypothesis incorrectly
• What is the correct hypothesis in a Type I error scenario?

  The null hypothesis is correct
• When is a Type I error more likely to occur?

  When the significance level is too high
• What is another name for a Type II error?

  False Negative
• What does a Type II error involve?

  Rejecting the alternative hypothesis incorrectly
• What is the correct hypothesis in a Type II error scenario?

  The alternative hypothesis is correct
• When is a Type II error more likely to occur?

  When the significance level is too low
• What significance level do psychologists typically favor?

  The 5% level of significance
• Why do psychologists favor the 5% level of significance?

  It balances Type I and Type II error risks