Critical Reasoning: Argument Flaw Questions
Computer Crimes Detective: A suspect monitored by our team was witnessed logging into Website X. Soon thereafter, Website X crashed due to a Trojan virus attack, causing damages estimated at millions of dollars. The same suspect also logged into Website Y. An hour after the suspect signed out of Website Y, it was attacked by the same virus and, subsequently, crashed. This strongly suggests that the suspect is either a hacker who is using this virus to shut websites down, or an unwitting user infected with the virus.
A major flaw in the detective's argument above is that
Incorrect.
[[snippet]]The fact that the second attack ensued an hour after the suspect had signed out does not constitute a logical flaw since the time of infection and the time of activation are not necessarily the same.
Nonetheless, there is definitely a flaw in the detective's argument. As always with Argument Flaw Questions, it can be found by analyzing the way the detective arrives at the conclusion. Look for an assumption made by the detective which isn't necessarily true.
Incorrect.
[[snippet]]This answer choice challenges the validity of the premises by raising the possibility that the suspect in the first case is not the same person as the one involved in the second case. However, we never question the premise(s) in Critical Reasoning questions. The premises are the factual basis we accept as true. If the argument is flawed, the flaw exists in the argument's conclusion or in an assumption underlying the conclusion. If the premises state it is the same suspect, it is enough to eliminate this answer choice.
This is a clear case of content vs. logic in Critical Reasoning questions. Knowing more about computers does not help you solve the question. On the contrary, it makes incorrect and irrelevant answer choices seem more appealing.
Anyway, there is definitely a flaw in the detective's argument. As always with Argument Flaw Questions, it can be found by analyzing the way the detective arrives at the conclusion. Look for an assumption made by the detective which isn't necessarily true.
Incorrect.
[[snippet]]Neither the conclusion nor the premises say anything about the person who wrote the virus. This topic is out of the scope of the argument. As with all Argument Flaw Questions, the flaw can be found by analyzing the way the detective arrives at the conclusion. Look for an assumption made by the detective which isn't necessarily true.
Incorrect.
[[snippet]]The cases of Websites X and Y share two similar characteristics:
- They were both attacked and shut-down by the same virus
- The same suspect logged into both of them
This already constitutes a pattern, and therefore there is nothing flawed about the way the detective connected these facts. However, the detective arrives at the conclusion that this particular suspect is the one who transferred the virus (whether intentionally or unwittingly).
This conclusion presupposes something that is not necessarily correct. Where's the flaw in the detective's logic?
Excellent work!
[[snippet]]The detective has her eye on the suspect since the suspect logged into both websites around the time of the attacks. However, the detective's conclusion is that this particular suspect is the one who transferred the virus whereas this could have been done by anyone who was logged into the websites at the time, and is either a hacker or an unwitting infected user. The detective arrives at this conclusion based only on the fact that the suspect's visits occurred soon before or after the attacks. Therein lies the flaw in her argument.
