Hi Daniel,
The information on that slide came from this source: https://www.sciencedirect.com/science/article/pii/B9780407003101500178
In reflecting on this question, this section could likely use some clarification. The Westmead Post-Traumatic Amnesia Scale is a standardized, scored assessment. Because the raw numbers for that measure are unlikely to be relevant for the NCS exam, I chose to simplify post-traumatic amnesia severity by linking it to duration (which still holds up in the literature) because that is easier to remember – longer periods of amnesia are associated with more severe injuries.
Thanks for pointing this out, and I’m going to look into adding some clarification here!
Chrissy