1 / 17

One-Way ANOVA

One-Way ANOVA. Problem 3.26, when assumptions are violated. Estimates of terms:. We can estimate the mean response for Failure Time for problem 3.26 from the data by which is called the Predicted Value and which is called the Residual Value.

Download Presentation

One-Way ANOVA

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. One-Way ANOVA Problem 3.26, when assumptions are violated

  2. Estimates of terms: We can estimate the mean response for Failure Time for problem 3.26from the data by which is called the Predicted Value and which is called the Residual Value.

  3. OK, what about when things go wrongProblem 3.26 data

  4. Plot that data

  5. Put in means and error bars

  6. Plot Residuals vs. Predicted

  7. A clear problem exists but run the test(s) for equal variances

  8. What to do, what to do….. Use Box-Cox transformation to transform the data!!!!!!!!!!!!!!

  9. Do the transformation and..

  10. Plot again

  11. Residuals vs. Predicted

  12. Testing equal variances

  13. Now Normality Plot of Residuals

  14. Test of Normality Goodness-of-Fit Test Shapiro-Wilk W Test W Prob<W 0.985985 0.9869 Note: Ho = The data is from the Normal distribution. Small p-values reject Ho.

  15. Whew, now do ANOVA….

  16. Compare Trt. groups with Tukey

  17. Reporting results after the analysis of transformed data • The purpose of diagnostics is to make sure that the assumptions are at least approximately correct, in which case the p-values reported for significance tests of means comparisons are valid. • In reporting results, such as means of treatment groups, generally use the untransformed or raw data. • Transformations of the data are used to obtain valid p-values, summaries of the original (untransformed or raw) data are used to report results.

More Related