Self-study
Support Three-year-old Sara and her playmate Michael are both ill and have the same symptoms. █████ ████ ████ ████████ █████ ██████████ ████ ████████ ███ ███ ████ ███████ ██ ███████ █████ █████ ███████ ██████████ ████ ███ ████ █ █████████████ ██████████ ███████ ███ ██████ ████ ████████ ██ ████ ███ ███████ ████ ████ ███ ██ ██████████ ███ █ █████████████ █████████ ███████
Summarize Argument
The author concludes that Sara definitely does not have a strep infection, despite having some symptoms of one. Why? Because Sara has the same symptoms as Michael, and the two of them play together every day. This leads to the sub-conclusion that Sara probably has the same illness as Michael. And Michael definitely doesn’t have a strep infection.
Identify and Describe Flaw
The author draws a conclusion about what must definitely be the case based on evidence about what is probably the case. The conclusion is that Sara “definitely” doesn’t have strep, because Michael definitely doesn’t have strep. However, Sara and Michael only “probably” have the same illness.
1.
The reasoning in the argument ██ ██████ ███████ ███ ████████
a
presupposes what it ████ ███ ██ █████
The author doesn’t presuppose that Sara doesn’t have strep—this conclusion is reached based on evidence about Sara’s symptoms matching with those of her playmate Michael, who doesn’t have strep.
b
mistakes the cause ██ █ ██████████ ██████████ ███ ███ ██████ ██ ████ ██████████
The author isn’t making any claims about cause and effect.
c
fails to distinguish ███████ █████ █████████████ ██████████ ██ ███ ███ █████ ███ ████ ██████ █████████████ ██████████ ██ ███ █████
The difference between acute and less severe strep infections isn’t relevant to the argument—the question is just whether Sara might have strep, not what type of strep she might have.
d
treats evidence that ███ ██████████ ██ ████████ ████ ██ ██ ████ ████████ ███████████ ███ █████████ ██ ███ ██████████
The author reaches the conclusion that Sara definitely doesn’t have strep based on evidence that Sara probably has the same non-strep illness as Michael.
e
makes a general █████ █████ ██ ██████████ ████████ ████ ██ ███ ██████████ █████████ ███ ██████████ ██████ ████ ████ ███ ████ ████████ ██ █████████
The author never makes a general claim about any groups based on examples taken to be representative. The argument is just about individual children, groups are irrelevant.