Use of the Concept of Transparency in the
Design of Hierarchically Structured Systems
This paper deals with the design of hierarchically
structured programming systems.  It develops 
a method for evaluating the cost of requiring programmers
to work with an abstraction of a real machine. 
 A number of examples from hardware and software
are given as illustrations of the method.
CACM July, 1975
Parnas, D. L.
Siewiorek, D. P.
