13. Is the Hadrian’s Wall curtain wall continuous?

No trace of the curtain wall and ditch has ever been found between Milecastles 73 and 76 as the Wall crosses Burgh Marsh. Some scholars have suggested that there was no need for a wall and ditch and associated milecastles (74 and 75) and turrets (73A, 73B, 74A, 74B, 75A, 75B) over this stretch of marshland but, as archaeologists are fond of pointing out, absence of evidence is not evidence of absence.

Further reading: Breeze 2006

One thought on “13. Is the Hadrian’s Wall curtain wall continuous?

  1. “but, as archaeologists are fond of pointing out, absence of evidence is not evidence of absence”

    It seems archaeologists are wrong, since absence of evidence _is_ evidence of absence:

    Absence of proof is not proof of absence. In logic, A->B, “A implies B”, is not equivalent to ~A->~B, “not-A implies not-B”.

    But in probability theory, absence of evidence is always evidence of absence. If E is a binary event and P(H|E) > P(H), “seeing E increases the probability of H”; then P(H|~E) < P(H), "failure to observe E decreases the probability of H". P(H) is a weighted mix of P(H|E) and P(H|~E), and necessarily lies between the two. If any of this sounds at all confusing, see An Intuitive Explanation of Bayesian Reasoning.

    http://lesswrong.com/lw/ih/absence_of_evidence_is_evidence_of_absence/

Comments are closed.