  Similar to the idea of relative projectivity, we introduce the notion of
relative subprojectivity, which is an alternative way to measure the
projectivity of a module. Given modules $M$ and $N$, $M$ is said to be {\em
$N$-subprojective} if for every epimorphism $g:B \rightarrow N$ and
homomorphism $f:M \rightarrow N$, then there exists a homomorphism $h:M
\rightarrow B$ such that $gh=f$. For a module $M$, the {\em subprojectivity
domain of $M$} is defined to be the collection of all modules $N$ such that $M$
is $N$-subprojective. A module is projective if and only if its subprojectivity
domain consists of all modules. Opposite to this idea, a module $M$ is said to
be {\em subprojectively poor}, or {\em $sp$-poor} if its subprojectivity domain
is as small as conceivably possible, that is, consisting of exactly the
projective modules. Properties of subprojectivity domains and $sp$-poor modules
are studied. In particular, the existence of an $sp$-poor module is attained
for artinian serial rings.
