Choosing a Statistical Test

• What is the first step in choosing a statistical test?

  Identify if it's a test of difference
• What are the types of designs for tests of difference?

  • Unrelated Design
  • Related Design
  • Repeated Measures Design
  • Matched Pairs Design
• What statistical test is used for nominal data in unrelated design?

  Chi-Squared
• What statistical test is used for ordinal data in unrelated design?

  Mann-Whitney
• What statistical test is used for interval data in unrelated design?

  Unrelated t-Test
• What statistical test is used for nominal data in related design?

  Sign Test
• What statistical test is used for ordinal data in related design?

  Wilcoxon
• What statistical test is used for interval data in related design?

  Related t-Test
• What tests are used for association or correlation?

  Chi-Squared, Spearman's rho, Pearson's r
• What factors should be considered when choosing a statistical test?

  • Difference or Correlation
  • Experimental Design for Tests of Differences
  • Levels of Measurement
• Why is it important to check the aim or hypothesis of the original study?

  To determine if a difference or correlation is needed
• What are the characteristics of nominal data?

  • Data is in the form of categories
• What are the characteristics of ordinal data?

  • Data is ordered in some way
  • Lacks precision based on subjective opinion
• What are the characteristics of interval data?

  • Based on numerical scales
  • Includes units of equal precisely defined size