Reading Comprehension

PT144 · S1 · P4 · Q26 Karl Popper

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Passage A

Passage A

The author presents and mildly critiques the ideas of Karl Popper regarding positive and negative evidence.

She starts out acknowledging the merits of his contribution. Negative evidence is definitely more powerful than positive evidence, since negative evidence has the power to prove a theory wrong, whereas positive evidence only shows that "so far, it's always been correct".

The rest of the first paragraph involves a series of attributions to Popper. Frequently, if an author is taking pains to separate someone else's ideas from her own, it's because a disagreement is around the bend. We can also see a negative attitudinal marker with the work "hyperbolic", which means exaggerating to an unrealistic degree.

Paragraph 2 delivers on our suspicions with a "However" author pivot. The second paragraph stresses that Popper goes overboard in acting like , since in the real world it's messier than that.

Testing scientific theories (to see whether we get positive or negative evidence, i.e. matching the predictions vs. not-matching the predictions) means assuming that other theories are correct, that your measuring instruments are working correctly, and potentially other assumptions.

So when negative evidence is found, it isn't immediately clear what that's telling us: it could be telling us, as Popper is thinking, that the theory we're testing is wrong but it could just be that one of our other theories is wrong, or that something went awry with the measurement.

Passage B

As we start the second passage, we're listening attentively for the first signs of Overlap. In the second sentence, we see "auxiliary assumptions" (which to me sticks out, because prior to Passage A, I had never heard the expression "auxiliary premises" before).

So we pause and possibly re-read that part of Passage A to dial in the meaning / significance of auxiliary assumptions to Passage A:

when a measurement doesn't match Theory A's predictions, - maybe Theory A is wrong - maybe an auxiliary assumption is wrong (e.g. Theory B is wrong. Idea X is wrong. Our instruments failed)

Passage B then takes us through two different examples.

Uranus Mercury

Measure U's orbit M's orbit doesn't didn't match didn't match match Newton's theory Newton's theory theory Reason for negative evidence

Aux. assump = wrong. Theory = wrong. We'd assumed there At first we thought weren't any planets aux assump of no nearby Uranus, planets near M was because we wrong, but once hadn't found Einstein's math Neptune yet worked, we found out Newt's theory was wrong.

26.

It can be inferred that the author of passage B would be likely to be most skeptical of which one of the following ideas mentioned in passage A?

  1. Popper's main contribution to the

    Out of Scope: Popper

    Passage B had nothing to say about Popper, so we have no ammunition to say it would disagree with a claim about Popper.

    3% picked this

  2. Correct

    Positive evidence plays no role

    Why this is right

    This isn't what we expected, but since this claim is so strongly worded, supporting someone disagreeing with it is a low bar. Can we get from Passage B that "positive evidence sometimes, plays some role in supporting a theory?" Yes, B's final sentence says that "when Einstein's predictions matched the observed orbit of Mercury (positive evidence in favor of Einstein's theory), this led to increased confidence in Einstein's theory".

    Skill tested: Author Opinion · how this choice captures the passage's function is the move to repeat next time.

    76% picked this

  3. Auxiliary premises are usually needed

    Trap

    Unsupported Disagree Position: Passage B probably agrees Since passage B was all about analyzing the auxiliary premises that went into the Uranus and Mercury conundrums, it seems like we only have support for B agreeing with this answer. We don't have anything in B that would support "most scientific theories do not need any auxiliary premises".

    5% picked this

  4. There is a logical asymmetry

    Unsupported Disagree Position

    Do we have any way to say that Passage B thinks that "positive and negative evidence are logically symmetric"? No, that's an extreme position. And in fact, the final sentence shows some asymmetry, since Mercury's orbit was negative evidence for Newton (leading to its rejection) and positive evidence for Einstein (leading only to increased confidence).

    10% picked this

  5. Scientific research involves generating bold

    Unsupported Disagree Position

    Do we have any way to say that Passage B thinks that "scientific research does not involve making bold theories and then attempting to refute them"? No, passage B never discusses anything like that.

    6% picked this

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