An extension of the Dirac procedure for the quantization of constraine
d systems is necessary to address certain issues that are left open in
Dirac's original proposal. These issues play an important role especi
ally in the context of nonlinear, diffeomorphism invariant theories su
ch as general relativity. Recently, an extension of the required type
was proposed using algebraic quantization methods. In this paper, the
key conceptual and technical aspects of the algebraic program are illu
strated through a number of finite dimensional examples. The choice of
examples and some of the analysis is motivated by certain peculiar pr
oblems endemic to quantum gravity. However, prior knowledge of general
relativity is not assumed in the main discussion. Indeed, the methods
introduced and conclusions arrived at are applicable to any system wi
th first class constraints. In particular, they resolve certain techni
cal issues which are present also in the reduced phase space approach
to quantization of these systems. (C) 1994 American Institute of Physi
cs.