CHAPTER 14 Nonparametric methods to accompany Introduction to business statistics fourth edition, by ronald m. Weiers Presentation by priscilla Chaffe -Stengel Donald n. stengel o 2002 The Wadsworth Group
CHAPTER 14: Nonparametric Methods to accompany Introduction to Business Statistics fourth edition, by Ronald M. Weiers Presentation by Priscilla Chaffe-Stengel Donald N. Stengel © 2002 The Wadsworth Group
l Chapter 14- Learning objectives Differentiate between nonparametric and parametric hypothesis tests Determine when a nonparametric test should be used instead of its parametric counterpart ppropriately apply each of the nonparametric methods introduced C 2002 The Wadsworth Group
Chapter 14 - Learning Objectives • Differentiate between nonparametric and parametric hypothesis tests. • Determine when a nonparametric test should be used instead of its parametric counterpart. • Appropriately apply each of the nonparametric methods introduced. © 2002 The Wadsworth Group
l Chapter 14 Key terms Nonparametric tests Wilcoxon signed friedman test rank test. randomized block One sample design Paired samples · Sign test, paired Wilcoxon rank sum samples test, two independent Runs test for samples randomness ° Kruskal- Wallis test,· Lilliefors test for three or more normality independent samples C 2002 The Wadsworth Group
Chapter 14 Key Terms Nonparametric tests • Wilcoxon signed rank test: – One sample – Paired samples • Wilcoxon rank sum test, two independent samples • Kruskal-Wallis Test, three or more independent samples • Friedman test, randomized block design • Sign Test, paired samples • Runs test for randomness • Lilliefors test for normality © 2002 The Wadsworth Group
l Nonparametric Tests Advantages: Disadvantages: Fewer assumptions Sample data usea less about the population efficientl > Shape Power of nonparametric >>Variance analysis lower Valid for small samples Places greater reliance Defined over a range of on statistical tables if computer statistical variables nominal and ordinal scales included package or spreadsheet not being used Calculations simple C 2002 The Wadsworth Group
Nonparametric Tests • Advantages: – Fewer assumptions about the population »Shape »Variance – Valid for small samples – Defined over a range of variables, nominal and ordinal scales included – Calculations simple • Disadvantages: – Sample data used less efficiently – Power of nonparametric analysis lower – Places greater reliance on statistical tables if computer statistical package or spreadsheet not being used © 2002 The Wadsworth Group
l Wilcoxon Signed rank Test One sample Requirements: Variable -Continuous data Scale- Interval or ratio scale of measurement The Research Question(H1): Test the value of a single population median, m,>,<mo Critical value/Decision rule: w, Wilcoxon signed rank test C 2002 The Wadsworth Group
Wilcoxon Signed Rank Test, One Sample • Requirements: – Variable - Continuous data – Scale - Interval or ratio scale of measurement • The Research Question (H1 ): Test the value of a single population median, m {, >, <} m0 • Critical Value/Decision Rule: W, Wilcoxon signed rank test © 2002 The Wadsworth Group