• Design is the reverse of analysis: one starts with the Answer (the Specification), and one has to work back to the beginning (circuit configuration and element values). Therefore, only analysis that can be worked backwards is worth doing. This is Design-Oriented Analysis.
   

• Design-Oriented Analysis is the process of guiding and controlling the algebra so that the result is a Low-Entropy Expression, defined as one in which the terms are ordered, or grouped, so that additional insight is obtained into the relative importance of the various contributions to the result. This is the source of the additional information needed for design, and substitutes for the missing equations that would be needed to solve formally for the number of unknowns.

An initial circuit diagram is analyzed, and the result compared with the specification. If it doesn't match, an "open-loop" adjustment is made to the circuit diagram, and the analysis is repeated in the hope that the result will come out closer to the specification. When the analysis result is a High-Entropy Expression, little guidance is provided on what elements to change in the circuit diagram.

Design-Oriented Analysis is a "closed-loop" process:

When the analysis result is a Low-Entropy Expression, any discrepancy between the analysis result and the specification becomes an "error signal" which can be "fed back" to suggest an adjustment to the circuit configuration or element values. The key is that a Low-Entropy Expression can be "inverted", or "worked backwards", because the ordering and grouping of terms discloses their contributions to the result.