Q4 - In polluted industrial English cities

[marosheg]

For the correct answer choice (D), how can a diseases which was "eradicated" return? This answer choice seems to in fact provide evidence against the claim that pollution eradicated it, since it returned when cities became less polluted?

[bbirdwell]

Here's the argument:

Fact:
black spot and tar spot disappeared during the Industrial Revolution

Conclusion:
Likely that air pollution eradicated them.

We want to strengthen this conclusion. Essentially, it's a causal relationship -- pollution causes disease to disappear. We want a new piece of evidence that supports this causal idea.

(A) doesn't help

(B) is irrelevant

(C) is totally irrelevant

(D) says air pollution went away, then the diseases returned. Hmm. Maybe.

(E) is no help -- that they were the only ones does nothing to support the causal relationship above.

I see what you mean about the definition of the word "eradicate," however all other choices are easy eliminations, and this choice does support the causal relationship between pollution and the presence of the disease. No disease --> pollution, no pollution --> disease.

You're right that it's not an all-star, amazing, totally verify the reasoning kind of strengthen answer. It's just better than the other 4.

[kky215]

In order to strengthen a causal conclusion, you can provide an example to prove that
1) when the cause happened the effect did happen
2) when the cause did NOT happen, the effect did NOT happen

answer choice D does the latter of the above two options.

Here, the cause is the "air pollution" and the effect is "eradication of the diseases"
When the cause did NOT happen --> the effect did NOT happen
(less polluted) --> (no eradication of diseases aka diseases return)

HTH

[VendelaG465]

would it be wrong to diagram it like this instead? air poll. ---> - no diseases

[ohthatpatrick]

You wouldn't diagram anything in this argument, because there are no conditional words present. The previous poster was just using arrows to communicate the idea of cause and effect.

Say that I had migraine headaches, but they stopped occurring once I started swimming every morning.

I'd be tempted to conclude that my swimming caused my migraine relief.
What's the best way to test this hypothesis?

Stop swimming and see if the headaches come back.

If the I stop swimming (no cause) and I no longer have headache relief (no effect), then I am highly convinced that swimming has helping my migraines go away.

This is the most common form of Strengthening a causal hypothesis.

It can also take this form:
In a three month study of people with migraine headaches, those who started swimming regularly experienced the most migraine relief. Scientists hypothesized that the swimming caused the headache relief.

Which would strengthen?
(A) The people in the study who swam the least had the smallest amount of migraine relief.

This is the same idea as "no cause, no effect" ... the LESS you were exposed to the cause, the LESS effect you felt.