Practitioners are often asked by insurers, funders and clients to provide a percentage rating for the likelihood of success, but the figure they produce may be arbitrary or misleading. Young points out some hazards in the modern trend of assigning percentages.
He writes of buckets, Bayesian probability and the dangers of bias and assumption. Moreover, courts are run by humans.
Young says: ‘‘By and large, people are bad at understanding probability, not least because of heuristics such as representativeness, availability, anchoring and confirmation bias.
‘Humans are also very bad at understanding randomness and… suffer from their own inbuilt cognitive biases. Considerable research in the behavioural sciences in recent years shows that people routinely misjudge by minimalisation the likelihood of unlikely events (so-called “Black Swans”) occurring.’
