Statistics Help @ Talk Stats Forum - Regression Analysis
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Linear regression, linear models, nonlinear regressionenTue, 24 Oct 2017 07:01:48 GMTvBulletin60http://www.talkstats.com/images/misc/rss.pngStatistics Help @ Talk Stats Forum - Regression Analysis
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Include or Exclude a Variable in Regression ?
http://www.talkstats.com/showthread.php/70467-Include-or-Exclude-a-Variable-in-Regression?goto=newpost
Mon, 23 Oct 2017 12:42:27 GMTDear all,
Dr Timothy Z Keith advised that a new variable should not be included unless it is
a common cause (associated with both dependent...Dear all,

Dr Timothy Z Keith advised that a new variable should not be included unless it is
a common cause (associated with both dependent variable and factor).

On the other hand, Dr Samprit Chatterjee suggested that we should ask 2 questions
before such decision. Those 2 questions are :

1) is the coefficient of the new variable significant ?
2) Did the new variable change the coefficients of other variables substantially ?

Finally Dr Wayne Winston suggested that our decision may be based on p values
and t values.

Their advice are so different, which one should I follow ?

Thank you very much in advance.

Sincerely
Marty
]]>Regression Analysismartinlhttp://www.talkstats.com/showthread.php/70467-Include-or-Exclude-a-Variable-in-Regression<![CDATA[Linear regression with only these data σx/σy =1.2]]>
http://www.talkstats.com/showthread.php/70457-Linear-regression-with-only-these-data-σx-σy-1.2?goto=newpost
Sun, 22 Oct 2017 16:02:31 GMTI have to demonstrate a linear relation between two variables X and Y using these data: σx/σy = 1.2. :mad: Small size effect required.

Test statistic tα = (b-β)/SE(b)

Can anyone help me, please?
]]>Regression AnalysisangbeeMultiple regression multigroup analysis in Amos
http://www.talkstats.com/showthread.php/70451-Multiple-regression-multigroup-analysis-in-Amos?goto=newpost
Sat, 21 Oct 2017 23:25:11 GMT B between two groups. The results of the standardised path coefficients (SPC) are...]]>I am testing the hypothesised effect in a model using SEM A -> B between two groups. The results of the standardised path coefficients (SPC) are Group 1: spc = 0.334 p < 0.001;
Group 2: spc = 0.316 p = 0.181. I would have expected the effect of group 2 to be also significant although it is worth noting that there are differences in the group sizes (group 1 = 72 group 2= 189). Is this an issue caused by the difference in the group sizes?
]]>Regression AnalysisHansihttp://www.talkstats.com/showthread.php/70451-Multiple-regression-multigroup-analysis-in-Amos