Bioequivalence and Bioavailability Forum

Dear d_labes,
Thanks for the clarification. I would like to rephrase question 3 as it seems I did not get the correct message out.
Considering I am using only the LSMEANS option for differences between more than 2 treatments (lets say: A-B, B-C & A-C) then, "I often see similar standard errors for each of those differences even though their point estimates may be very different" I am citing an example output from chapter 4 of “Bioequivalence and Statistics in Clinical Pharmacology by Patterson and Jones”); Example 4.5 for 3 treatments
         Differences of Least Squares Means

                                              Standard
Effect     formula    _formula    Estimate       Error     
formula    R          S            -0.3410     0.03851     
formula    R          T            -0.1497     0.03849     
formula    S          T             0.1912     0.03871

I removed the last few columns of the code, but the output comes from this statement;
  lsmeans formula/pdiff cl alpha=0.1;.

This is at least one case where the standard errors differ in the 3rd decimal place, but more than often I see the same standard errors. I am just curious as to why this happens?

Regarding the last point, Thanks HS. I will search more before I get back.

Thanks,
Vijay