Self-study
Police chief: Support During my tenure as chief, crime in this city has fallen by 20 percent. ████ ██ ███████ ███ ██████ ██ ██ ████████ █████████ █████ ████ █████████ █████ ████ ███ ███████ ██████ █████████ ██ ███ █████ ████ ███ ████ ██████
Summarize Argument: Phenomenon-Hypothesis
The police chief hypothesizes that their policing strategy was the cause of a 20 percent reduction in crime in their city. The only support for this claim is a correlation in timing: the chief's tenure and the crime reduction happened during the same time period.
The police chief draws a causal hypothesis based on an observed correlation. In order to weaken this argument, we can propose an alternative cause for the crime reduction, such as a change to criminal laws which decriminalized certain actions. We can also look for evidence that is inconsistent with the chief's conclusion, for example evidence that crime rates are typically not affected by policing strategies but rather by other factors.
11.
Which one of the following, ██ █████ ████ █████ ████ ████████ ███ ██████ ███████ ███████████ ███ ███ ████ ██ ██████
a
The crime rate ██ ███ ██████ ███████ ████ ██ █████ █████████████ ██████ ████ ██ ████ █████ ███████
The police chief’s policing strategy can still have caused a 20% reduction in crime, even if that reduction leaves the city with an above-average crime rate. This doesn't affect the argument.
Illusory inconsistency
Illusory inconsistency
Answer is attractive because it seems to (but doesn't actually) contradict the premises or conclusion.
b
The crime rate ██ ███ ██████ ███████ ████ ██ ██████ ███ ████ ██ ███ ███████ ███████ ██████ ███ ███████ ██████ ██████
The chief's claim is just that the new policing strategy caused a decrease in crime since the chief's tenure began. Whatever changes in crime rate were going on before this chief started aren't relevant.
Illusory inconsistency
Illusory inconsistency
Answer is attractive because it seems to (but doesn't actually) contradict the premises or conclusion.
c
The crime rate ██ ███ ██████ ███████ ████ ████ █████████████ ██████ ███ █████ ███ █████ ██ ███ ███████ ███████ ████ ██ ███████ ████
This doesn't affect the argument, because the chief's claim is about an overall crime reduction—whether that reduction happened gradually or suddenly doesn't change that it happened.
d
The crime rate ██ ███ ███████ ██ █ █████ ████ ██ █████ ██ ███████ ██████ ███ ██████ ███████ ███████
This weakens the argument by presenting countervailing evidence. Although it doesn't directly give us an alternative cause, this suggests that there was some other factor lowering crime country-wide, so maybe the chief's strategy didn't do much after all.
Alternate explanation
Alternate explanation
Weaken: Introduce or support an alternate explanation for a phenomenon.
Strengthen: Helps to eliminate an alternate explanation for a phenomenon.
e
The variation in █████ █████ ███████ █████████ █████ ██ ███ ████ ██ ███████ ██ ███ ██████ ███████ ████ ████ ██ ████ █████ ███████
Like (A), this comparison to other cities doesn't raise any suggestion that the chief's strategy wasn't the true cause of the crime reduction, so it doesn't weaken.