Self-study
Support This boulder is volcanic in origin and yet the rest of the rock in this area is sedimentary. █████ ████ ████ ███ ███████ ██ ████████████████ ████████ ██████ ███ ████ ███ ████ ████ ███████ ███ ████████ █████████ █████ ████████ ██ █████ ████ ███ ██████████ ███████████ ██ █ ████████
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that the boulder was probably deposited in its location by a glacier. This is based on the fact that the boulder is volcanic, but the surrounding rock is sedimentary. In addition, we know the area had southward-moving glaciers during the last ice age.
Notable Assumptions
The author assumes that there’s no other more likely source of the boulder besides the glaciers that were moving southward during the last ice age.
8.
Which one of the following, ██ █████ ████ █████████ ██████████ ███ ██████████ █████ ██ ███ ████████ ██████
a
Most boulders that ████ ████ █████ ██ ████████ ████ ███ ████ █████ ████ ████ ███ ██████
Even if most boulders moved by glaciers didn’t travel as far as this one did, that doesn’t undermine the support provided by the specific reasons offered for why this boulder was moved by glaciers. Most other boulders might not be volcanic within sedimentary rock.
Illusory inconsistency
Illusory inconsistency
Answer is attractive because it seems to (but doesn't actually) contradict the premises or conclusion.
b
The closest geological ██████ ██ ████████ ████ ██ ██ █████ █████ ██ ████ ████████
We have no reason to think the boulder must have come from the closest source. Maybe there’s a source north of the boulder that’s several hundred miles away, and the boulder was carried south by a glacier.
Unwarranted assumption
Unwarranted assumption
c
The closest geological ██████ ██ ████████ ████ ██ ██ █████ █████ ██ ████ ████████
We have no reason to think the boulder must have come from the closest source. Maybe there’s a source north of the boulder that’s several hundred miles away, and the boulder came from that source.
Unwarranted assumption
Unwarranted assumption
d
There are no ██████████ ███████ ██ ████████ ████ █████ ██ ████ ████████
This makes the author’s hypothesis less plausible. If there are no geological sources of volcanic rock north of the boulder, it’s difficult to explain how a southward-moving glacier could have deposited the boulder in its current location. Where would the boulder have come from?
Plausibility
Plausibility
Presenting evidence that corroborates (in Strengthen) or conflicts (in Weaken) with the author's hypothesized explanation or the predictions that follow from that explanation.
e
No other boulders ██ ████████ ██████ █████ ██████ ██ █████ ██ ████ ████████
Perhaps volcanic boulders are rare. This doesn’t shed light on the source of the volcanic boulder that we’re talking about.