[SRILM User List] Does '-omit' work?

[Dmytro Prylipko]

Dear Andreas,

I found that using -omit and -observed options does not influence on
the calculation of perplexity.
I trained an skip-LM for filled pauses as you advised me (generated
n-grams, where FPs were skipped from context).
But when I apply it to the test data it does not matter which
combination of options do I use for the hidden-vocabulary:
<FP> -omit -observed
<FP> -omit
<FP> -observed
 or just
<FP>

For each case I have the same perplexity value. However, it differs
when the hidden vocabulary is empty or contains another token, so I
can conclude it works.
Could you tell me if I am doing everything right? Why the options do not work?

Sincerely yours,
Dmytro Prylipko.