stats tests

• Mann Whitney U Test


  • DV produces ordinal data
  • independent measures
  • difference between IV levels
• Wilcoxon


  • DV produces ordinal data
  • Repeated measures
  • Difference between IV levels
• Chi-squared


  • DV produces nominal data
  • independent measures
  • difference between IV levels
• Binomial sign test


  • DV produces nominal data
  • repeated measures
  • difference between IV levels
• Spearman's Rho


  • variables produce at least ordinal data
  • exploring relationship between co- variables
  • uses a correlational design
• Rule of R


  No "R" in test name means the calculated value has to be equal to or less than the critical value to be significant.
• Type 1 errors


  • false positive
  • the test is significant but result was due to chance due to setting too lenient significance levels
  • eg using 10% probability rather than 5% (5% is a compromise between type 1 and type 2 error)
• Type 2 error 


  • false negative
  • test is not significant but result was due to chance by settinf too strict significance levels
  • eg using 1% (5% is a compromise between type 1 and type 2 error)
• degrees of freedom


  used in Chi-squared instead of N

  (no. of rows-1)x(no. of columns-1)
• nominal data


  data as totals of names categories or the number of participants saying "yes/no"
• ordinal data


  data as points along a scale such that the points fall in order but aren't necessarily equal gaps between those points