statistical testing

• significance 


  results have not occurred by chance
• probability


  the 5% significance level

  the more stringent 1%
• critical value


  comparison with calculated value to determine significance
• criteria for sign test 


  testing for difference

  nominal data

  repeated measures
• sign test steps


  1. convert to nominal data
  2. add up pluses and minuses
  3. S=less frequent sign
  4. compare calculated value of S with critical value