Self-study
During the three months before and the three months after a major earthquake in California, students at a college there happened to be keeping a record of their dreams. █████ ████████████ ███ ███████████ ████ ██ ███ ████████ ████████ ████████ █████ ████████████ ██████ ███ ████ ███ ███████ █ █████ ██ ███████ ████████ ██ ███████ ███ ███ █████ ███████████ ██ ██████████ ████ ████████ █████ ███████ ██████ ████ ██ ███ ████████ ██ ███████ ████████ ████████ █████ ████████████ ██ ██ ██ █████ ████ ████████████ ██ ██████████ ███ █████ ██████ ██ █████ █████ ████████████
Summarize Argument: Phenomenon-Hypothesis
The author's hypothesis is that experiencing an earthquake can cause people to dream about earthquakes. This conclusion comes from a study where a high proportion of students in California who had experienced an earthquake later dreamed about earthquakes, while students in Ontario who had never experienced an earthquake mostly didn’t dream about earthquakes.
Notable Assumptions
The author assumes that the students in California mostly hadn’t dreamed about earthquakes before they experienced one. If half of the Californian students had already been dreaming about earthquakes before they experienced one, this would call the author's conclusion into question.
9.
Which one of the following, ██ █████ ████ ███████████ ███ █████████
a
Before the California ███████████ ██ ████ ██ ███ ████████ ██ ██████████ ████ ██ █████ ██ ███████ ████████ ██████ █████ ████████████
This answer choice tells us that there was a clear increase in the number of Californian students who dreamed about earthquakes after they experienced one. This strengthens the conclusion that the earthquake caused these dreams.
Alternate explanation
Alternate explanation
Weaken: Introduce or support an alternate explanation for a phenomenon.
Strengthen: Helps to eliminate an alternate explanation for a phenomenon.
b
The students in ██████████ ████ ███████ ██ █ █████ ████████ ██████ ███ █████ █████████████ ███ ███ ████████ ██ ███████ ████ ████
This would weaken the author's argument. Perhaps the students in Ontario did dream about earthquakes, but didn't remember those dreams because they hadn’t studied dream recollection.
c
Before they started ███████ ███████ ██ █████ ███████ ████ ██ ███ ████████ ██ ██████████ ███ ███████████ ██ █████ ███ ███████████
This just tells us that perhaps the Californian students had prior experience of earthquakes. This neither strengthens nor weakens the author's claim that experiencing an earthquake can cause dreams about earthquakes.
Directionally wrong
Directionally wrong
Answers that, if they have any effect, do the opposite of what we want (weaken when we're trying to strengthen, or strengthen when we're trying to weaken).
d
The students in ███████ ████████ ██████ ████ ██████ ████████ ███ ████████ ████ ███ ████████ ██ ██████████ ████
Irrelevant. We're interested in how many participants dreamed about earthquakes at all, not in how many dreams each participant had.
e
The students in ███████ ███ ████████ ██████ ██████ █████ ███████████ ████████ ███ ██████ ██ ██████ ████████ █████ ███ ██████████ ███████████
This suggests that some of the Ontario students may have heard about the earthquake and dreamed about it afterward. But this doesn't change the fact that none of the Ontario students had directly experienced an earthquake, and that the majority of them didn't dream about earthquakes. This doesn't strengthen the author's conclusion.