lsmeans not estimable, but lsmean differences are [R for BE/BA]

posted by d_labes  – Berlin, Germany, 2019-03-03 14:07 (794 d 12:05 ago) – Posting: # 19988
Views: 1,597

Dear ElMaestro,

» So, R is telling me that it can derive a difference of lsmeans but it can't derive the lsmeans individually. I find this quite annoying, possibly hard to believe.

With the last sentence I agree totally.
Nevertheless such situations exist :yes:.

I have sometimes encounter this situation in SAS using the LSMeans statement in Proc GLM.

See the FAQs for emmeans for an R implementation. Look under point 8.

Why this is so precisely is beyond my intellectual reach. Had to tackle such things like "estimability theory". Oh my dear!

My own explanation, quick and dirty only for myself, goes like this: Some factors constellations used in LSMeans which lead to the NonEst result cancel out if you derive LSMeans for the difference and therefore the latter are estimable.

Regards,

Detlew

Complete thread:

Activity
 Admin contact
21,444 posts in 4,482 threads, 1,509 registered users;
online 15 (0 registered, 15 guests [including 3 identified bots]).
Forum time: Thursday 03:13 CEST (Europe/Vienna)

In matters of style, swim with the current;
in matters of principle, stand like a rock.    Thomas Jefferson

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz
HTML5