Wigmore charts

I’m speaking at the EBM+ project meeting at UCL on Monday on a topic that I’ve been working on for a couple of months now. Very briefly, the talk is about Wigmore charts, and ways that we might use them to support clinical decision-making.

Wigmore chart
Wigmore chart

Wigmore charts (like the example here that I’ve borrowed from Anderson, Schum and Twining’s excellent 2005 book) were originally designed to support complex legal arguments. Imagine that you are trying to build a complex legal case: trying to convict someone of fraud, say. Wigmore charts are a tool for showing how these complicated legal argument works. Here, the “ultimate probandum” is the legal verdict that you are trying to reach (in this case, something like “x knowingly defrauded y”). The chart shows the steps of the legal argument that support this final verdict, all the way down to the many pieces (often, in court cases, many thousands of them) on which the case is build.

My current thought is that these inferential networks would be useful in medicine too, particularly when dealing with complex decisions about evidence. I think that we might use Wigmore charts, or something similar, as an heuristic (see Chow’s recent BJPS paper for a cracking introduction). But to say more would give the game away.

You can have a look at my slides here – [2mB .pdf].

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