# DesignWIKI

Fil Salustri's Design Site

2015.01.09 11:13
design:abduction

# Abduction

Abduction is a form of logical inference commonly associated with design (and other disciplines).

Abduction is distinguished from other inferencing schemes by its modus ponens: $p \Rightarrow q, q; p$

In this case, knowing q the consequent is knowing what we want to achieve in designing something – knowing how the world ought to be, knowing how it will be different with a new product in it, knowing what the requirements are. The premise that $p \Rightarrow q$ is saying that we know the introduction of some product $p$ will lead to the expected future state $q$. Our conclusion is that $p$ is the product we want.

One very important feature of abduction is that though $p$ is one solution, it is not the only solution. That is, abduction lets one identify only one of possibly many solutions.

This accounts for the diversity of products that ostensibly all do the same things, and also the multiplicity of possible design solutions for any problem.

There appear to be several kinds of abduction. The one shown is one that is often associated with design, medicine (diagnostics), jurisprudence (arguing from evidence to explanation), astronomy (Big Bang inferred from cosmic background radiation), etc. [Eek00]