1 / 80

Chapter 15: Nonparametric Statistics

2. Learning Objectives. Nonparametric Statistical MethodsWilcoxon TestThe Wilcoxon Rank SumUsing the Wilcoxon Test with a Quantitative ResponseNonparametric Estimation Comparing Groups. 3. Learning Objective 1: Nonparametric Statistical Methods. Nonparametric methods are especially useful:When

iria
Download Presentation

Chapter 15: Nonparametric Statistics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

    1. 1 Chapter 15: Nonparametric Statistics Section 15.1 How Can We Compare Two Groups by Ranking?

    2. 2 Learning Objectives Nonparametric Statistical Methods Wilcoxon Test The Wilcoxon Rank Sum Using the Wilcoxon Test with a Quantitative Response Nonparametric Estimation Comparing Groups

    3. 3 Learning Objective 1: Nonparametric Statistical Methods Nonparametric methods are especially useful: When the data are ranks for the subjects, rather than quantitative measurements. When it’s inappropriate to assume normality.

    4. 4 Learning Objective 1: Example: How to Get A Better Tan Experiment: A student wanted to compare ways of getting a tan without exposure to the sun. She decided to investigate which of two treatments would give a better tan: An “instant bronze sunless tanner” lotion A tanning studio

    5. 5 Subjects: Five female students participated in the experiment. Three of the students were randomly selected to use the tanning lotion. The other two students used the tanning studio. Learning Objective 1: Example: How to Get A Better Tan

    6. 6 Results: The girls’ tans were ranked from 1 to 5, with 1 representing the best tan. Possible Outcomes: Consider all possible rankings of the girls’ tans. A table of possibilities is displayed on the next page. Learning Objective 1: Example: How to Get A Better Tan

    7. 7 Learning Objective 1: Example: How to Get A Better Tan

    8. 8 For each possible outcome, a mean rank is calculated for the ‘lotion’ group and for the ‘studio’ group. The difference in the mean ranks is then calculated for each outcome. Learning Objective 1: Example: How to Get A Better Tan

    9. 9 For this experiment, the samples were independent random samples – the responses for the girls using the tanning lotion were independent of the responses for the girls using the tanning studio. Learning Objective 1: Example: How to Get A Better Tan

    10. 10 Suppose that the two treatments have identical effects. A girl’s tan would be the same regardless of which treatment she uses. Then, each of the ten possible outcomes is equally likely. So, each outcome has probability of 1/10. Learning Objective 1: Example: How to Get A Better Tan

    11. 11 Using the ten possible outcomes, we can construct a sampling distribution for the difference between the sample mean ranks. The distribution is displayed on the next page. Learning Objective 1: Example: How to Get A Better Tan

    12. 12 Learning Objective 1: Example: How to Get A Better Tan

    13. 13 Graph of the Sampling Distribution: Learning Objective 1: Example: How to Get A Better Tan

More Related