On the other hand, some variables have no clear reference level, but present ordered levels and the reference level will be, usually, one of the endpoints or, less frequently, the central level. The
p
k
{\displaystyle p_{k}}
are the probabilities that the corresponding
y
k
{\displaystyle y_{k}}
will be unity and
1
p
k
{\displaystyle 1-p_{k}}
are the probabilities that they will be zero (see Bernoulli distribution). 37
Consider a generalized linear model function parameterized by
{\displaystyle \theta }
,
Therefore,
and since discover this
Y
{
0
,
1
}
{\displaystyle Y\in \{0,1\}}
, we see that
Pr
(
y
X
;
)
see post
{\displaystyle \Pr(y\mid X;\theta )}
is given by
Pr
(
y
X
;
)
=
h
(
X
)
y
(
1
h
(
X
)
)
(
1
y
)
. .