Geologist: A new method for forecasting

Answer choices

1. A

   Bad Trigger Match4% picked this

   Even if an earthquake-forecasting method makes predictions within a very narrow range on the Richter scale, this method is not likely to be

   The phrase "even if" is not conditional. It basically means "irrelevant". If you were diagramming, "Even if A, B", you'd basically just say "B." Even if it rains, = I'm coming I'm coming to your show to your show. So we don't really need to consider it part of the "rule" this answer is providing. The word "unless" is conditional. The idea attached to the unless goes on the left side, but in negated form. We use the shorthand "if-not" to remind ourselves "Left side - negated". Here, it said "unless predictions are reliable", so we would put "if predictions are not reliable" on the left of the arrow. predictions are ? method is not likely not reliable to be useful The right side matches the Conclusion, so this is worth considering. But does the left side match the Evidence? Were we told that the new method makes unreliable predictions? No, the first sentence says the new method "reliably predicted" several earthquakes.

   4%
2. B

   Correct64% picked this

   An earthquake-forecasting method is unlikely to be useful unless its predictions always differentiate earthquakes that are barely noticeable from ones

   Why this is right

   Again, we see an "unless", so we put the idea attached to it on the left, but negated (if-not). If predictions do not always method differentiate small quakes ? unlikely to from big earthquakes be useful The right side matches our Conclusion. Does the left side match our Evidence? Were we told that the new method's predictions do not always differentiate between barely noticeable quakes and ones that result in substantial destruction? Yup! They can predict only within a 2.5 range, which means it could be anywhere from a barely noticeable one to a very destructive one. Thus, according to this rule, the new method is unlikely to be useful.

   Skill tested: Sufficient Assumption · how this choice captures the argument's function is the move to repeat next time.

   64%
3. C

   Weak Conclusion Match1% picked this

   An earthquake-forecasting method has not been shown to be useful until it has been used to reliably predict

   This ends up giving us the same conditional rule as (A). The words "until" and "unless" work the same way (if-not). So we put the idea attached to until on the left, but negated. If a forecasting method has not been has not been used to ? shown to reliably predict a large be useful number of earthquakes Does the right side match our Conclusion? Not quite. We're supposed to be proving that the new method is unlikely to be useful. This is only proving it has not yet been shown to be useful. That's way weaker. That's just an agnostic statement of, "We don't know whether it is or isn't useful." Since the right side of this rule doesn't actually give us an idea as strong as the Conclusion (unlikely to be useful), we can throw out this answer. For what it's worth, it feels pretty fair to say the Evidence does match the trigger. This new method has only reliably predicted several earthquakes, so it doesn't seem like it has yet reliably predicted a large number of earthquakes.

   1%
4. D

   Unrelated to Goal4% picked this

   Several well-established methods for forecasting earthquakes can predict within much narrower ranges than two and a half points

   Since this answer isn't providing a proving mechanism for the Conclusion wording, "If X is true, then unlikely to be useful", it's worthless to us.

   4%
5. E

   Weak Premise Match27% picked this

   An earthquake-forecasting technique, even a perfectly reliable one, will probably be of little use if its predictions never distinguish between earthquakes that are imperceptibly

   This answer is worth considering, since it's providing a mechanism to prove "probably be of little use", which is equivalent to "unlikely to be useful". Like (A), we can ignore the "even if" qualifier, which adds nothing. The word "if" is always a sufficient indicator (put on Left). The models predictions never distinguish between ? probably be imperceptibly small and of little use catastrophically damaging Do we know that this model's predictions never distinguish between imperceptibly small and catastrophically damaging? No. That's a very strong idea that we weren't told. We know it can't differentiate between marginally perceptible and considerable damage, but that's not the same as knowing it never distinguishes between imperceptibly small and catastrophically bad. If real numbers help, an earthquake that is 4.0 is barely noticeable. A 6.5 is bad, but not leveling-the-city bad. It just means things will violently shake. Some property will be damaged. Meanwhile, an imperceptible quake would be like 3.0 or lower (unless you're right near the epicenter), and a catastrophic quake would be like 7.0 or higher. This method can't distinguish between two numbers that are within 2.5 of each other, but it still might sometimes be able to distinguish between two numbers that are at least 4.0 away from each other (like an imperceptibly small and catastrophically bad one).

   27%