Computer security experts correctly maintain that computer passwords are a less secure means of protecting one’s information than are alternative security options like fingerprint scanners. But computer passwords are not going to be replaced by these other options anytime soon. The alternative security options remain significantly more expensive to employ, and they can replace passwords only if they become standard on most of the world’s computers.

Summary
The author concludes that computer passwords are not going to be replaced by alternate security options like fingerprint scanners. Why? Because in order for those options to replace passwords, they must become standard on most of the world’s computers. In addition, those other options are a lot more expensive than computer passwords.

Missing Connection
We can prove that computer passwords won’t be replaced by the alternative options if we can show that the alternatives won’t become standard on most of the world’s computers.

One way to prove that would be to establish that if the alternatives are a lot more expensive than computer passwords, then they won’t become standard on most of the world’s computers.

A
There are ways to make computer passwords a more secure means of protecting one’s information.
(A) doesn’t establish that the alternative methods won’t become standard on most of the world’s computers. So (A) doesn’t establish that the alternatives won’t replace computer passwords.
B
Any security option that is no more expensive to employ than computer passwords provides less security than computer passwords.
(B) concerns alternatives to computer passwords that are not more expensive than passwords. But those aren’t the alternatives we’re talking about. (B) doesn’t establish that the more-expensive alternatives won’t become standard on most of the world’s employers.
C
Most computer security experts do not believe that computer passwords will be replaced by an alternative security option anytime soon.
What experts believe doesn’t establish that the alternatives won’t become standard on most of the world’s computers. Maybe what the experts believe is wrong?
D
Security options that are significantly more expensive to employ than computer passwords will not become standard on most of the world’s computers anytime soon.
(D) establishes that the more-expensive alternatives won’t become standard on most of the world’s computers anytime soon. In connection with the last premise — which tells us that in order to replace passwords, those options have to become standard on most computers — (D) establishes that those options cannot replace passwords anytime soon.
E
As soon as a security option is developed that is not significantly more expensive to employ than computer passwords, computer passwords will be replaced as a security measure.
(E) establishes a condition under which computer passwords WILL be replaced. This doesn’t establish that computer passwords will NOT be replaced soon. If you think (E) does, you’re confusing sufficiency and necessity.

3 comments

Statistics show clearly that in those countries with the most severe penalties for driving while intoxicated, a smaller percentage of drivers have traffic accidents involving alcohol use than in other countries. This refutes those who claim that would-be drunk drivers will not be deterred by the prospect of severe penalties.

Summarize Argument
The author argues that drunk drivers are deterred by the prospect of severe penalties. This is because statistics show that countries with the most severe penalties for drunk driving have a smaller percentage of alcohol-related traffic accidents when compared to other countries.

Notable Assumptions
The author assumes that there are no other factors, such as cultural differences, in the countries with harsh punishments for drunk driving that would explain the lower rates of drunk driving accidents.

A
The countries with the largest populations do not have severe penalties for driving while intoxicated.
This is irrelevant to the reasoning of the argument. The size of countries with/without severe penalties does not impact the causal relationship between severe penalties and the rates of drunk driving accidents.
B
Very severe penalties against driving while intoxicated are in effect only in countries in which alcohol use is rare.
This weakens the argument by calling out one of the author’s main assumptions. If alcohol use is already rare in countries with the strictest penalties, then the low rate of alcohol-related driving accidents might be due to low alcohol consumption.
C
The higher a country’s speed limits, the more frequent traffic accidents tend to be in that country.
A country’s speed limits are irrelevant to the relationship between strict penalties and the rate of drunk driving accidents. You need to make a lot of unwarranted assumptions for this answer choice to work.
D
Only a relatively small minority of those who drive while intoxicated are actually apprehended while doing so.
Whether or not drunk drivers are apprehended is irrelevant to the relationship between strict penalties and the rate of drunk driving accidents. Also, this does not address the comparison between countries with/without strict penalties.
E
All countries impose severer penalties on those who cause accidents while driving intoxicated than on those who are merely apprehended while driving intoxicated.
This is irrelevant to the argument because it does not address how the severity of penalties impacts the rate of drunk driving accidents. This fact does not change anything about the argument.

5 comments

Many species of plants produce nectars known as extrafloral nectories (EFNs), which are known to attract certain ants that defend the plants against leaf-eating insects. Recently, greenhouse experiments have found that jumping spiders jump onto plants with active EFNs six times more often than they jump onto plants without EFNs, and regularly eat the nectar. So, like the ants, jumping spiders apparently defend EFN-producing plants against leaf-eating insects.

Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that jumping spiders defend EFN-producing plants against leaf-eating insects. He supports this by noting that ants that display behavior similar to that of the spiders defend the plants. He then cites experiments showing that the spiders land on plants with active EFNs six times more often than on those without EFNs, and they regularly eat the plant's nectar.

Notable Assumptions
The author assumes that there’s no alternative explanation for the spiders’ attraction to the EFN-producing plants, simply because the spiders’ behavior is similar to the ants’ behavior. He implicitly rules out all other explanations. But maybe the spiders just land on the plants for food and have a neutral or even negative effect on the plants’ health.

A
For many species of nectar-producing plants, productivity is increased when a plant is protected from leaf-eating insects.
Irrelevant—this doesn’t rule out any alternative explanations for the spiders’ behavior. It makes sense that plants are more productive when protected from leaf-eating insects, but (A) doesn’t address whether the spiders themselves are actually protecting the plants.
B
In field experiments, the introduction of jumping spiders into an environment was followed by a significant increase in the population of EFN-producing plants.
This strengthens the author’s hypothesis by validating a prediction that would follow from it. If his hypothesis were true, we’d expect to see the plants thriving and reproducing when the spiders are introduced, since the spiders protect them from leaf-eating insects.
C
Some species of EFN-producing plants cannot survive without some outside agent protecting them from leaf-eating insects.
Irrelevant— this fails to address whether jumping spiders are protecting the plants from leaf-eating insects and thus fails to strengthen the argument.
D
Experiments with types of spiders other than jumping spiders suggest that these other types of spiders do not defend EFN-producing plants.
Irrelevant— the argument is only concerned with whether or not the jumping spiders defend EFN-producing plants. The effect of other types of spiders on EFN-producing plants doesn’t matter.
E
Regions with large populations of ants also tend to have large populations of EFN-producing plants.
Irrelevant— we already know that certain ants protect EFN-producing plants from leaf-eating insects, so it makes sense that areas with lots of ants also have lots of EFN-producing plants. But (E) fails to address whether jumping spiders also protect these plants.

8 comments

When using a manufactured pattern to make clothing, a tailor alters the pattern to accommodate any future distortion of the fabric. Also, unless the clothing is to be worn by a person whose measurements precisely match the pattern size, the tailor alters the pattern to fit the wearer exactly. Thus, a professional tailor never blindly follows a pattern, but always adjusts the pattern to fit the wearer exactly.

Summary
The author concludes that a professional tailor always alters a pattern to fit the wearer. Why? Because any tailor always alters a pattern to fit the wearer, unless the wearer’s measurements already match the pattern to begin with.

Note that the first sentence provides no support for the conclusion.

Missing Connection
The conclusion is about professional tailors, but the premise refers only to tailors more broadly.

Also, the conclusion is that professional tailors always alter the pattern, no exceptions. But the premise allows for an exception: tailors in general alter the pattern unless the wearer’s measurements already match the pattern.

The premise would lead to the conclusion if we knew that for professional tailors specifically, the exception never applies. That is, for a professional tailor, the wearer’s measurements never match the pattern.

A
Most manufactured patterns do not already accommodate the future distortion of fabrics that shrink or stretch.
This says nothing about professional tailors and so can’t help us reach the conclusion. Also, fabric distortion is irrelevant. The argument is focused solely on how tailors change patterns to fit the wearer. Nothing in the stimulus suggests fabric distortion has any part in that.
B
At least some tailors who adjust patterns to the wearer and to the fabrics used are professional tailors.
Too weak. The fact that some professional tailors sometimes adjust the pattern to fit the wearer isn’t enough to reach the conclusion that all professional tailors always adjust the pattern. Also, note that any details about adjusting fabrics are irrelevant to the argument.

C
The best tailors are those most able to alter patterns to fit the wearer exactly.
This refers to the best tailors, but the conclusion is about professional tailors. Because (C) tells us nothing about professional tailors, it can’t help us reach the conclusion.
D
All professional tailors sew only for people whose measurements do not exactly match their chosen patterns.
We know from the argument’s premise that if a person’s measurements do not exactly match the chosen pattern, a tailor will always alter the pattern. (D) adds that professional tailors always sew for such people. So professional tailors always alter the pattern.

E
A professional tailor can always estimate exactly how much a fabric will shrink or stretch.
Fabric distortion is a red herring—it’s irrelevant to the argument. The argument is focused solely on how tailors change patterns to fit the wearer. Nothing in the stimulus suggests fabric distortion has any part in that.

13 comments

Typically, a design that turns out well has gone through many drafts, each an improvement over the previous one. What usually allows a designer to see an idea’s advantages and flaws is a sketch of the idea. The ways in which the sketch appears muddled or confused tend to reveal to the designer ways in which the design has been inadequately conceptualized.

Summary
A design that turns out well has usually gone through many drafts, with each improving on the last. Sketching an idea usually allows a designer to see an idea’s flaws and advantages. Areas where the sketch feels confused reveals where the design has been inadequately conceptualized.

Strongly Supported Conclusions
A design that turns out well has usually involved the designer sketching the design many times to see areas where the sketch has been inadequately conceptualized.

A
The designs that turn out best go through the most drafts.
This is unsupported because we don’t have enough information to state the superlative that the drafts that turn out best go through the most drafts. We only know that good designs in general typically have many drafts.
B
Many good designs have emerged from design ideas that were flawed.
This is strongly supported because if good designs are the products of drafting an idea many times, and drafts are useful because they help a designer see where a sketch is flawed, many of those good ideas had initial flaws that were improved on subsequent drafts.
C
Designs that do not turn out well have not gone through many drafts.
This is unsupported because many drafts is usually necessary for good designs, not sufficient as this answer choice sees it.
D
Designs whose initial conceptualization was inadequate rarely turn out well.
This is unsupported because the initial conceptualization may be able to be refined over a series of many drafts even if the initial conceptualization was inadequate.
E
A designer will never see advantages and flaws in a design idea without the aid of a sketch.
This is unsupported because while a sketch helps designers see flaws, it is too strong to say that sketches are a necessary condition of seeing flaws as answer choice E implies.

5 comments