Wigmorean Analysis and Fact Management

In one line

Wigmorean analysis is a method of setting out every evidential step in a case as a diagram, so that each inference can be examined on its own.

In the wording a student can write in an examination: Wigmorean analysis, from J. H. Wigmore's The Principles of Judicial Proof of 1913, is a method of analysing a mass of evidence into its individual inferences. It uses two instruments: a Chart, in which each evidential fact is a numbered symbol placed according to what it tends to prove, and a List, in which each number is translated into a sentence. Fact management is the modern name for the wider skill of organising and analysing the facts of a case, of which Wigmore's method is the classical systematic form.

Why the topic is here

Because everything in this book has been about single inferences, and a case is not a single inference. It is hundreds of them, most of them never stated, arranged in chains and in parallel, some supporting, some contradicting, some bearing on nothing.

Wigmore's insight was that this can be written down. If each step is set out separately, each can be tested separately, and the whole can be seen at once instead of held in the head. The rest of the method is machinery for doing that.

And it is the natural close to Module IV, because it is definition and division applied to a case: every proposition has to be stated exactly, and every proposition has to be sorted by what it does.

The two termini

Wigmore's section 2 supplies the vocabulary and it is the first thing to learn.

Evidence is always a relative term. It signifies a relation between two facts: the factum probandum, the proposition to be established, and the factum probans, the material evidencing that proposition. The former is necessarily hypothetical; the latter is brought forward as a reality for the purpose of convincing the tribunal that the former is also a reality.

Wigmore adds that no sure comprehension of any evidential question can be had unless this double aspect is distinctly pictured in each instance. That is the whole method in one sentence: for every piece of material, ask what it is offered to prove, and for every proposition, ask what is offered to prove it.

The chain. The ultimate probandum is the final proposition the party must establish. Below it sit the propositions that would establish it, and below those the propositions that would establish them, until the bottom of the chain is reached in something a witness saw or a document shows. Wigmore notes that between the two extremes lies the mass of ordinary evidence, for which at least two distinct steps of inference are required: from the fact of an assertion to the matter asserted, and then from the matter asserted to another matter.