  When two or more subsystems of a quantum system interact with each other they
can become entangled. In this case the individual subsystems can no longer be
described as pure quantum states. For systems with only 2 subsystems this
entanglement can be described using the Schmidt decomposition. This selects a
preferred orthonormal basis for expressing the wavefunction and gives a measure
of the degree of entanglement present in the system. The extension of this to
the more general case of n subsystems is not yet known. We present a review of
this process using the standard representation and apply this method to the
geometric algebra representation. This latter form has the advantage of
suggesting a generalisation to n subsystems.
