The new terror threat ratings
The new terror threat ratings have sparked a discussion of the meaning of the words used. We have no problem with certain and not expected. The others – expected, probable, possible – fit into a schema that is linked to assessments of probability. They no doubt have specific numbers attached to them. Strictly speaking, something that is possible can happen but is not likely to happen, whereas something that is probable can happen and is likely to happen. Something that is expected is something that we are confident will actually happen.
The trouble is that in general use, these words overlap in meaning. Possible has one definition along the lines given above but it has another that is the equivalent of probable. The first definition states that something can happen but makes no assessment of its likelihood. A simple statement of capability. But the second says that something can happen and is likely, and at that point possible is a synonym for probable. If you were asked ‘Are you going to the beach tomorrow?’ You could say ‘It’s quite possible’ or ‘It’s quite probable’ or ‘I expect so’, all of these responses meaning that you intend to go but are not quite sure yet. The boundaries between these words in general use are not clear-cut.
The definitions given of probable and possible don’t help. Expected and probable both talk about ‘credible specific information’ and a target and intention and capability. Possible gives the distinction of a limited intention and capability. But you don’t want a system where people have to have the definitions with the words to be able to follow it. And in this case, there are two words where the definitions don’t help.
There is an argument for saying that possible in its strict sense should be the base line. Anything is possible but is it expected? That gives us the next line of not expected. Anything is possible but is it probable, expected, certain? The fact that we are arguing about these words and their hierarchy is not good.
There is also the difficulty that words can work in a hierarchy like this where their meanings are apparent in relation to each other, but then not function very well on their own. The warnings will have to say ‘The threat is probable – remember that’s above possible and below expected’. On its own probable could mean anything. We are used to the low – medium – high hierarchy so if someone says medium danger we can fill in what comes above and below it. But this set is unfamiliar and difficult.
The colours are the most successful aspect of the new system. Red shading through to green. My response to these was simple and what was intended. But expected, probable, possible? If I hear any of these I’m heading for the hills.
Read more about the National Terrorism Threat Advisory System.