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Computer Modeling Failed During the Ebola Outbreak
the_newsbeagle writes: Last fall, the trajectory of the Ebola outbreak looked downright terrifying: Computational epidemiologists at Virginia Tech predicted 175,000 cases in Liberia by the end of 2014, while the CDC predicted 1.4 million cases in Liberia and Sierra Leone. They were way off. The actual tally as of January 2015: A total of 20,712 cases in Guinea, Liberia, and Sierra Leone combined, and in all three countries, the epidemic was dying down. But the modelers argue that this really wasn't a failure, because their predictions served as worst-case scenarios that mobilized international efforts.
Garbage in ... Garbage out - GIGO
That computer simulation failed simply because all the input that the program got fed with were erroneous
Which is just akin to crying wolf. Next outbreak: "They're predicting 2 million infected, but remember ebola? It never got that bad. Take your time."
Well, IF there hadn't been a very robust response, it could easily have been that bad.
People who work in population dynamics know that the models are based on a very crude understanding of the disease and ultimately general epidemiological assumptions. The fact that there are basic assumptions is sometimes disguised in the process of making fancy computer models.
These models may be the best predictions that people can make. However, GIGO (garbage in, garbage out) still applies. However, sometimes the best predictions are not good enough since they can be very misleading.
(I used to work on similar models and became disenchanted; I need to post anonymously.)
The problem with blaming prediction models after the fact is that the models were based on the assumption of current and continued support. Ebola just like the Y2K bug was everything the disaster it may have been had it not been for the efforts involved in preventing it.
End result, all the people who did the hard work making the world aware of the problem are blamed for crying wolf.
...maybe the crazy predictions opened enough eyes to get the ball rolling on containment...therefore nullifying the predictions?
The way the model results are reported needs to change. The worst case results were presented to the public as the expected outcome. This is something between highly deceptive and unethical. (think yelling "Fire!" in a crowded movie theater.) The best, worst and average outcomes from the model need to be reported. Perhaps even two sets of best, worst and average outcomes. One with large scale intervention and one with zero intervention.
A very simple way to think about when you know the model has failed: The model has failed when it makes 100 predictions with 95% certainty and more than 5 of the actual outcomes are outside the bounds defined by the best and worst outcomes. Note: I said SIMPLE.
The modelers need to be careful about what they say. Next time they predict armageddon, no one will take them seriously.
if we let things go to shit like we normally do. Because of this we didn't let things go to shit and so the model was wrong...? How is this a bad thing, or a failure of the model. This is like when people say regulations aren't needed anymore because the abuses they were put in place to stop have stopped. They stopped for a reason people. Figure it out, it's not that difficult.
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No, it doesn't show that. The point of the computer models is not to predict exactly how bad the outbreak will be. What good would that do? All you have to do to find out how bad the outbreak will be is wait. What computer models do is give us some kind of idea of how seriously we should take the situation. For that, the models did a fine job. They probably shouldn't have been bandied about so much on the news, but that's not a problem with the science--that's a problem with the science reporting, which is a well known problem.
But it's really, really frustrating when people predict a possible bad outcome and suggest steps be taken to prevent it, and then steps are taken, and then the bad outcome doesn't happen, possibly because the steps were taken (it's never possible to know for sure) and then somebody says "you cried wolf." No. Crying wolf is when you lie about a threat you know doesn't exist. The Y2K threat wasn't crying wolf, and this wasn't crying wolf. What both things were were attempts to mitigate a very real risk the severity of which was uncertain. The fact that we didn't have a massive breakdown in 2000, and that we didn't have an Ebola pandemic, are both really good outcomes.
But the modelers argue that this really wasn't a failure, because their predictions served as worst-case scenarios that mobilized international efforts.
so.... how about those climate models out there????
So, you're saying that climate models that do not reflect the mobilization of international efforts mean that we should not attempt to push for international efforts to ensure that those worst-case predictions do not happen?
Climate science is always evolving. Scientists learn more about the planet and how different aspects of our planet's behavior interact, and they discover new aspects through this process. I don't think there's a lot of argument that humans are taking huge carbon deposits that are the result of plants using carbon from the air as building material in their structures and reintroducing that carbon into the atmosphere again. The debate is what that does to climate.
Do not look into laser with remaining eye.
done precisely in order to encourage behavior that would change the inputs to the model.
Nobody looks at cigarettes today and says, "Gosh, nobody smokes anyway and death rates are coming down, there was no need for all that worry, smoke away!"
The whole point of the data in that case (and in this one) was to encourage the world to change behavior (i.e. alter the inputs) to ensure that the modeled outcome didn't occur.
To peer at the originally modeled outcome after the fact and say that it was "wrong" make no sense.
When we tell a kid, "finish high school or you're going to suffer!" and then they finish high school and don't suffer a decade down the road, we don't say "well, you didn't suffer after all, guess there was no point in you finishing high school!"
That would be silly. As is the idea that the modeling was wrong after the modeling itself led to a change in the behavior being modeled.
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spend their days posting, "Why in the hell do we vaccinate against polio? It's a scam! After all, how many people do *you* know that have ever had it? Hmmmm? Case closed!"
STOP . AMERICA . NOW
This is almost a cliche, it's exactly what happened after Y2K. We saw a potential threat, a huge one, and a way to prevent it. We mustered great resources to prevent it - and succeeded. But unlike in the movies those who prevented the threats were not celebrated - immediately afterwards they were accused of having made up the threat to justify the resources.
It's a fundamentally stupid failure of logic, but it happens over and over. If you manage to prevent a threat from realizing, people claim the threat was never real.
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