Chapter 17 Business Research Methods Donald Cooper Pamela

Chapter 17 Business Research Methods ä Donald Cooper ä Pamela Schindler Irwin/Mc. Graw-Hill ©The Mc. Graw-Hill Companies, Inc. , 2001

Chapter 17 Hypothesis Testing Irwin/Mc. Graw-Hill ©The Mc. Graw-Hill Companies, Inc. , 2001

Approaches to Click to edit Master title style Hypothesis Testing Slide 17 - 1 Classical Statistics äsampling-theory approach äobjective view of probability ädecision making rests on analysis of available sampling data Bayesian Statistics äextension of classical statistics äconsider all other available information Irwin/Mc. Graw-Hill ÓThe Mc. Graw-Hill Companies, Inc. , 2001

Click. Types to edit of Master title style Hypotheses Slide 17 - 2 Null äthat no statistically significant difference exists between the parameter and the statistic being compared Alternative älogical opposite of the null hypothesis äthat a statistically significant difference does exist between the parameter and the statistic being compared. Irwin/Mc. Graw-Hill ÓThe Mc. Graw-Hill Companies, Inc. , 2001

Click to of edit Master title. Testing style Logic Hypothesis Slide 17 - 3 Two tailed test änondirectional test äconsiders two possibilities One tailed test ädirectional test äplaces entire probability of an unlikely outcome to the tail specified by the alternative hypothesis Irwin/Mc. Graw-Hill ÓThe Mc. Graw-Hill Companies, Inc. , 2001

Click to edit Errors Master in title style Decision Testing Slide 17 - 4 Type I error äa true null hypothesis is rejected Type II error äone fails to reject a false null hypothesis Irwin/Mc. Graw-Hill ÓThe Mc. Graw-Hill Companies, Inc. , 2001

Testing for Statistical Click to edit Master title style Significance Slide 17 - 5 ä State the null hypothesis ä Choose the statistical test Select the desired level of significance ä Compute the calculated difference value Obtain the critical value ä Interpret the test Irwin/Mc. Graw-Hill ÓThe Mc. Graw-Hill Companies, Inc. , 2001

Click to edit Master title style Classes of Significance Tests Slide 17 - 6 Parametric tests äZ or t test is used to determine the statistical significance between a sample distribution mean and a population parameter ä Assumptions: ä independent observations ä normal distributions ä populations have equal variances ä at least interval data measurement scale Irwin/Mc. Graw-Hill ÓThe Mc. Graw-Hill Companies, Inc. , 2001

Click to edit Master title style Classes of Significance Tests Slide 17 - 7 Nonparametric tests äChi-square test is used for situations in which a test for differences between samples is required ä Assumptions ä independent observations for some tests only ä normal distribution not necessary ä homogeneity of variance not necessary ä appropriate for nominal and ordinal data, may be used for interval or ratio data Irwin/Mc. Graw-Hill ÓThe Mc. Graw-Hill Companies, Inc. , 2001

Clicktoto. Test edit Master style How the Nulltitle Hypothesis Slide 17 - 8 Analysis of variance (ANOVA) äthe statistical method for testing the null hypothesis that means of several populations are equal Irwin/Mc. Graw-Hill ÓThe Mc. Graw-Hill Companies, Inc. , 2001

Click to edit. Comparison Master title style Multiple Tests Slide 17 - 9 ä Multiple comparison procedures ätest the difference between each pair of means and indicate significantly different group means at a specified alpha level (<. 05) äuse group means and incorporate the MSerror term of the F ratio Irwin/Mc. Graw-Hill ÓThe Mc. Graw-Hill Companies, Inc. , 2001

Click. How to editto. Master style Selecttitle a Test Slide 17 - 10 ä Which does the test involve? one sample, two samples k samples If two or k samples, are the individual cases independent or related? ä Is the measurement scale nominal, ordinal, interval, or ratio? Irwin/Mc. Graw-Hill ÓThe Mc. Graw-Hill Companies, Inc. , 2001

Click to edit Master title. Test style K Related Samples Slide 17 - 11 Use when: ä The grouping factor has more than two levels ä Observations or subjects are ämatched. . . or äthe same subject is measured more than once ä Interval or ratio data Irwin/Mc. Graw-Hill ÓThe Mc. Graw-Hill Companies, Inc. , 2001