The Wigmorean chart method applies beyond the courtroom. Each diagram below maps a real-world
reasoning problem as a Directed Acyclic Graph — from a landmark criminal trial to scientific
reclassification to medical diagnosis. Nodes are discrete evidence items or intermediate inferences.
Gold arrows show inferential support; red dashed lines show counter-inferences that must be resolved.
Inferential support (three independent evidence chains converge)
Following Anderson & Twining’s Wigmorean methodology (Analysis of Evidence, 2005), the prosecution’s case
derives its power from convergence: three independent evidence streams — DNA blood matching Simpson at 1-in-170 million
across the crime scene, his vehicle, and his home; physical trace evidence linking a split pair of Aris Light gloves and
size-12 Bruno Magli shoe prints; and an unaccounted timeline with the Bronco absent during the murder window — all point to
a single physical-link inference. Motive evidence (documented domestic violence including a 1989 battery conviction) and
flight conduct (the Bronco chase with a disguise, passport, and cash) provide additional support. The defense
counter-inference attacks the convergence node itself: LAPD crime-lab contamination, Detective Fuhrman’s credibility
and racial bias, and the courtroom glove demonstration sought to sever the evidentiary chains from their conclusion.
The jury’s acquittal rested on resolving this counter-inference in Simpson’s favor — collapsing the physical-link
hub despite the prosecution’s convergent architecture.
Inferential support (evidence converges on failed criterion)
Counter-inference (geophysical definition: intrinsic properties should define planethood)
Ultimate probandum: reclassification as dwarf planet
Applied as a Wigmorean proof chart, the IAU’s 2006 reclassification of Pluto rests on three converging evidence
streams: Pluto shares its orbital zone with thousands of Kuiper Belt objects; its mass is only 0.07 times the
combined mass of other objects in its orbit (Earth, by contrast, is 1.7 million times the remaining mass in its zone);
and the 2005 discovery of Eris — 27% more massive than Pluto — made the definitional crisis unavoidable.
These three lines converge on a single penultimate inference: Pluto has not “cleared the neighborhood” around its
orbit, failing the third of three criteria established by IAU Resolution 5A. Pluto passes the other two (orbiting the
Sun, having sufficient mass for hydrostatic equilibrium), which is precisely why it qualifies as a “dwarf planet”
rather than a small Solar System body. The counter-inference — championed by planetary scientists including Alan
Stern and Kirby Runyon — attacks the IAU definition itself, arguing that intrinsic geophysical properties
(geological complexity, atmosphere, moons) should define planethood rather than orbital dynamics. This unresolved
counter-inference is why the debate persists two decades after the vote.
Inferential support (three diagnostic pillars converge on biopsy)
Counter-inference (IgA deficiency causes false negatives; other causes of villous atrophy)
Ultimate probandum: celiac disease confirmed
Celiac disease is notoriously difficult to diagnose because its evidence streams are individually ambiguous — only
their convergence is compelling. Three diagnostic pillars feed the central biopsy node: clinical presentation
(GI symptoms like chronic diarrhea and bloating, or extra-intestinal signs like iron deficiency, dermatitis herpetiformis,
and elevated liver enzymes); serology (tTG-IgA at 98% sensitivity, confirmed by EMA; titers >10× the upper limit
of normal approach certainty); and HLA genetics (DQ2/DQ8 — negative results effectively exclude the disease, but
~30% of the general population carries these alleles, so a positive result is necessary but far from sufficient).
The convergence hub is the duodenal biopsy — the gold standard — requiring at least four samples because villous
atrophy is patchy, classified by the Marsh system (Type 3 = diagnostic). Confirmation flows through the
gluten-free diet response: symptom resolution plus serological normalization. The counter-inference attacks
both serology and biopsy: IgA deficiency (~2–3% of celiac patients) produces false-negative serology,
while tropical sprue, Crohn’s disease, and non-celiac gluten sensitivity can mimic the histological picture.
This web of ambiguity is precisely why celiac disease takes an average of 6–10 years to diagnose.