文档介绍：CHAPTER 12 Analysis of Variance Tests
to pany
Introduction to Business Statistics
fourth edition, by Ronald M. Weiers
Presentation by Priscilla Chaffe-Stengel
Donald N. Stengel
© 2002 The Wadsworth Group
Chapter 12 - Learning Objectives
Describe the relationship between analysis of variance, the design of experiments, and the types of applications to which the experiments are applied.
Differentiate one-way, randomized block, and two-way analysis of variance techniques.
Arrange data into a format that facilitates their analysis by the appropriate analysis of variance technique.
Use the appropriate methods in testing hypotheses relative to the experimental data.
© 2002 The Wadsworth Group
Chapter 12 - Key Terms
Factor level, treatment, block, interaction
Within-group variation
Between-group pletely randomized design
Randomized block design
Two-way analysis of variance, factorial experiment
Sum of squares:
Treatment
Error
Block
Interaction
Total
© 2002 The Wadsworth Group
Chapter 12 - Key Concepts
Differences in es on a dependent variable may be explained to some degree by differences in the independent variables.
Variation between treatment groups captures the effect of the treatment. Variation within treatment groups represents random error not explained by the experimental treatments.
© 2002 The Wadsworth Group
One-Way ANOVA
Purpose: Examines two or more levels of an independent variable to determine if their population means could be equal.
Hypotheses:
H0: µ1 = µ2 = ... = µt *
H1: At least one of the treatment group means differs from the rest. OR At least two of the population means are not equal.
* where t = number of treatment groups or levels
© 2002 The Wadsworth Group
One-Way ANOVA, cont.
Format for data: Data appear in separate columns or rows, organized as treatment groups. Sample size of each group may differ.
Calculations:
SST = SSTR + SSE (definitions follow)
Sum of squares total (SST) = sum of squared differences between each indiv