Chapter Seven: Comparison of Two Groups

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Chapter Seven Comparison of Two Groups

• DBA 902
• Research Methods II
• J. Schreiber

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Various Types of Studies, Samples, and Variables

• Studies
• Longitudinal
• Cross-sectional
• Samples
• Independent
• Dependent
• Variables
• Binary/Dichotomous
• Response (dependent)
• Explanatory (independent)

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Comparing of Means

• The sampling distribution of the sample mean is
  approximately normal with mean mu when
• Then, the sampling distribution of the difference
  in such sample means is approximately normal with
  mean ___ and variance __________

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Comparing of Means

• Large-sample C.I. for mu2 mu1
• Significance Tests for mu2 mu1

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Comparing of Proportions

• The sampling distribution of the difference in
  sample proportions is approximately normal with
  mean ______ and variance
• _________________when

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Comparing of Proportions

• Large-sample C.I. for pi2 pi1
• Significance Tests for pi2 pi1

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Comparing of Means (small sample)

• Used when
• The C.I. for mu2 mu1 is then
• using a __ score and ______ d.f.

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Comparing of Proportions (small sample)

• Significance Test
• Ho
• Ha
• Conclusions

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Comparing Dependent Samples

• For means
• For proportions