Programming the statistical procedures from SAS

Standard error from glm

Regular Contributor
Posts: 234

Standard error from glm

Hi everyone.

I'm wondering if anyone could shed some light on this.

I don't understand why the confidence interval of the least squares means I manually calculated as

(logconc LSMEAN) plus/minus (1.96*Standard Error) is different from that produced by SAS.

My code is as below. Your help is greatly appreciated!

proc glm data=out order=internal;

  by Intervention;

  class Sample;

  model logconc=Sample / solution;

  lsmeans Sample / cl pdiff tdiff stderr e om;



Respected Advisor
Posts: 2,053

Re: Standard error from glm

There's no way we can answer your question.

We can't see your data, we can't see the calculations you did, and we can't see the SAS output.

Paige Miller
Valued Guide
Valued Guide
Posts: 684

Re: Standard error from glm

Posted in reply to PaigeMiller

Paige is right. One obvious thing: "1.96" is the t value with a large number of denominator df (say, df >30). The critical t value will be larger for small df.

Regular Contributor
Posts: 234

Re: Standard error from glm

Thanks very much Paige and Ivm for your reply Smiley Happy

Yes, I did it wrong by multiplying by 1.96 :smileysilly:

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