\begin{definition}[Definition:Convenience Sample]
Let $P$ be a population in the physical universe.
Let $S \subsetneq P$ be a sample.
Suppose that data about some individuals in $P$ are more easily accessible than data about others.
Then $S$ is a '''convenience sample''' {{iff}} the primary criterion for the construction of $S$ is the higher accessibility of data of certain individuals in $P$ over others.
That is, the objects in $S$ are the ones conveniently at hand.
\end{definition}