I'm not sure if "the opinion of current users of low-wattage bulbs as to their effectiveness" should affect the conclusion that recommends "Everyone should use low-wattage bulbs". Shouldn't the recommendation be made based on facts rather than opinions? Whether current users think they are effective or not, without facts backing it up, it's just an opinion and should not change the conclusion.

First, just because something is a quantifiable fact, does not automatically make it relevant. Second, I am assuming you are proposing that D would be a better answer than B in the example above, since the other answer choices are more readily seen as helpful to evaluating the support. The conclusion of the argument is, "their [low wattage bulbs] advantages to the homeowner are enormous, and therefore everyone should use low-wattage bulbs". Answer choice B regarding the profits of bulb sellers is interesting, but irrelevant. For example, just because a drug seller may make profits from selling you a prescription, that does not in and of itself impact the efficacy of the prescription and the advantage that drug gives you. However, the conclusion is saying that all homes in should switch to the low wattage bulbs. What if many people are allergic to them? What if they break very easily and the glass gets everywhere? What if they had a bad smell? The list can go on... So, before we accept that EVERYONE should do something, I think feedback from initial users would be very useful. Hope that helps.

I don't see any helpful to know questions under practice. Am I missing something?

I have had a couple of these question types come up under the advanced "Strengthen and Weaken" question sets under the Practice tab.

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Course: LSAT > Unit 1

Lesson 6: Logical Reasoning – Articles

Helpful to know | learn more

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How do you know what's useful to know?

Questions that fall into the "Identify what's helpful to know" category ask you to identify which choice’s information would help you evaluate the argument—in other words, what information, if you had it, would either strengthen or weaken the argument.

When we make decisions in everyday life, we use information in a similar way to come to a decision. If we wanted to evaluate a decision to switch jobs, it’s probably not enough to just say, “I’m going to quit my job and accept this new one, because the new job’s office is 3% closer than the old job’s office.” We need more information! For example, many people would want to compare salaries, cultures, benefits, company mission, growth opportunities.

How do we recognize this question type?

Look for questions that ask you for what would be helpful or useful:

Which one of the following would be most helpful to know in order to evaluate Dave’s theory?

It would be most useful to know which of the following in evaluating the politician’s argument?

Information about which one of the following would be LEAST useful in evaluating the argument?

Top tip: Look out for LEAST helpful questions. In the last example above, the question is essentially an “EXCEPT” question. You can rephrase it as, “Each of the following would be useful in evaluating the argument EXCEPT”—so, the four wrong choices will be useful, and the answer will not help us evaluate the argument at all.

Now let’s work through an example together, and we’ll offer some approaches that may help you.

Example

Millions of homes are now using low-energy lighting, but millions more have still to make the switch, a fact that the government and the home lighting industry are eager to change. Although low-wattage bulbs cost more per bulb than normal bulbs, their advantages to the homeowner are enormous, and therefore everyone should use low-wattage bulbs.

Information about which one of the following would be LEAST useful in evaluating the argument?

(A) the actual cost of burning low-wattage bulbs compared to that of burning normal bulbs

(B) the profits the home lighting industry expects to make from sales of low-wattage bulbs

(D) the opinion of current users of low-wattage bulbs as to their effectiveness

(E) the average life of a low-wattage bulb compared with that of a normal bulb

How might we approach this question type?

✓ Identify the conclusion and support
This may help you detect any gaps in the arguer’s journey from support to conclusion.

Conclusion

Everyone should use low-wattage bulbs

because

Support

Low-wattage bulbs cost more per bulb than normal bulbs, [but]
Their advantages to the homeowner are enormous.

Essentially, the arguer is in favor of low-wattage bulbs, because even though there’s one drawback (cost per bulb), they bring enormous advantages to the homeowner.

We didn’t account for the background details in analyzing the argument:

Millions of homes are now using low-energy lighting, but
Millions more have still to make the switch, a fact that the government and the home lighting industry are eager to change.

This information doesn’t actually contribute to the heart of the argument (the “what” and the “why”); what it does is set up the context for why the argument is taking place to begin with.

✓ Look for gaps
Does anything immediately feel like it’s “missing” from the argument? For example, the arguer does provide a drawback in cost, but doesn’t directly resolve that drawback. Cost could be an important factor to consider, but the only information the arguer provides to attempt to offset the higher cost is a vague reference to enormous advantages.

Top tip: Don’t panic! There could be several items missing from an argument, so don’t panic if you predict an answer that feels really strong but it’s not among the choices.

✓ Look for common patterns
Some patterns are more frequently seen on the LSAT than others. That doesn’t mean that the LSAT is limited to common patterns. But in your practice, you may become accustomed to seeing arguments such as:

“X and Y happened at the same time; therefore, X must have caused Y.”
”X has always happened in the past, so it’s sure to happen again this year.”
“The only possible results are X, Y, or Z. X is unlikely and Y is impossible, so Z is going to be the result.”

These are just a few common patterns you may see. In our example, we see the common pattern of weighing advantages and disadvantages, but we aren’t given any indication of what the advantages are and whether they outweigh the disadvantage of higher cost. We don’t even know if the higher cost is significant enough to warrant consideration. So this kind of thinking is a good start in considering what we’re missing.

✓ Test the choices by turning them into a question
You can try phrasing each choice as a question that needs to be answered, and then consider how opposite results would affect the argument. If one result would strengthen or weaken the argument and the opposite result would affect the argument in an opposite way as the first result, then the chances are very good that we have our answer.

However, don’t forget that this question is a LEAST useful question—that means that we’ll actually be eliminating choices that would help us evaluate the argument. This may feel a little abstract to you without practice, so click on the links below to try out each choice one at a time until you feel comfortable with this strategy.

(A) the actual cost of burning low-wattage bulbs compared to that of burning normal bulbs

As a question: What is the actual cost of burning low-wattage bulbs compared to that of burning normal bulbs?

Lower cost $\to$ ‍ this strengthens the argument and makes it more likely that we should switch to low-wattage bulbs—compared to normal bulbs, low-wattage bulbs cost more to buy, but they cost less to operate.
Higher cost $\to$ ‍ this weakens the argument—not only do low-wattage bulbs cost more to buy, but they also cost more to operate.

Because this information would help us evaluate the argument, and we’re asked for which choice would LEAST help us evaluate the argument, we can eliminate this choice.

(B) the profits the home lighting industry expects to make from sales of low-wattage bulbs

As a question: What are the profits the home lighting industry expects to make from sales of low-wattage bulbs?

High profits $\to$ ‍ this neither strengthens nor weakens the recommendation to buy low-wattage bulbs. Whether the home lighting industry expected to make high profits from these sales doesn’t affect whether homeowners should or shouldn’t use low-wattage bulbs instead of normal bulbs. The same is true of low profits, so we have the answer!

Because answering this question in any way doesn’t affect our ability to evaluate the argument, then this choice is the one that’s LEAST helpful to us.

(B) is the answer.

As a question: What is the specific cost of a low-wattage bulb compared with that of a normal bulb?

Much higher $\to$ ‍ this weakens the argument, because it makes the cited drawback more significant than it originally was. If a low-wattage bulb costs $150 c o m p a r e d w i t h a$ ‍1 normal bulb (just to use an exaggerated example), then it’s less likely that homeowners should use low-wattage bulbs.
Just a little bit higher $\to$ ‍ this strengthens the argument. We weren’t told how much higher the cost of low-wattage bulbs was, so if we learned that low-wattage bulbs cost $1.01 a n d n o r m a l b u l b s c o s t$ ‍1.00, it’s more likely that homeowners should use low-wattage bulbs.

Because this information would help us evaluate the argument, and we’re asked for which choice would LEAST help us evaluate the argument, we can eliminate this choice.

(D) the opinion of current users of low-wattage bulbs as to their effectiveness

As a question: What is the opinion of current users of low-wattage bulbs as to their effectiveness?

Low opinion $\to$ ‍ this weakens the argument because it provides an additional drawback to the use of low-wattage bulbs. Even though we were told that there are enormous advantages, the effect of a low opinion about effectiveness is that adds weight to the “don’t use low-wattage bulbs” side of the argument.
High opinion $\to$ ‍ this strengthens the argument because it adds weight to the side supporting low-wattage bulb use. It gives us a specific advantage that offsets the higher cost of low-wattage bulbs.

Because this information would help us evaluate the argument, and we’re asked for which choice would LEAST help us evaluate the argument, we can eliminate this choice.

(E) the average life of a low-wattage bulb compared with that of a normal bulb

As a question: What’s the average life of a low-wattage bulb compared with that of a normal bulb?

Short life $\to$ ‍ this would weaken the argument, because it adds a new comparative drawback to using low-wattage bulbs that wasn’t originally listed.
Long life $\to$ ‍ this would strengthen the argument, because it adds a new, specific advantage that could serve to offset the drawback of higher cost.

Because this information would help us evaluate the argument, and we’re asked for which choice would LEAST help us evaluate the argument, we can eliminate this choice.

Summary

✓ Identify the conclusion and support
✓ Look for gaps
✓ Look for common patterns
✓ Test the choices by turning them into a question

Common wrong choice types

The most common incorrect choice is one that offers information that might seem relevant, but it’s only relevant if you add your own assumptions. It’s generally a warning sign if you have to work hard to add information in order to justify a choice.

Try one on your own!

The ruins of the prehistoric Bolivian city of Tiwanaku feature green andacite stones weighing up to 40 tons. These stones were quarried at Copacabana, which is across a lake and about 90 kilometers away. Archaeologists hypothesize that the stones were brought to Tiwanaku on reed boats. To show this was possible, experimenters transported a 9-ton stone from Copacabana to Tiwanaku using a reed boat built with locally available materials and techniques traditional to the area.

Which one of the following would be most useful to know in order to evaluate the support for the archaeologists' hypothesis?

(Choice A)
whether the traditional techniques for building reed boats were in use at the time Tiwanaku was inhabited
(Choice B)
whether green andacite stones quarried at the time Tiwanaku was inhabited were used at any sites near Copacabana
(Choice C)
whether reed boats are commonly used today on the lake
(Choice D)
whether the green andacite stones at Tiwanaku are the largest stones at the site
(Choice E)
whether the reed boat built for the experimenters is durable enough to remain usable for several years

Takeaways

Most/least helpful questions are similar to strengthen/weaken questions, since you’re evaluating how certain information would affect an argument. Try to think in terms of “impact”, either positive or negative, as you add the information to the argument.
Keep practicing to separate the conclusion from its support—it will help you detect gaps more easily!

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Anni W
Posted 4 years ago. Direct link to Anni W's post “I'm not sure if "the opin...”
I'm not sure if "the opinion of current users of low-wattage bulbs as to their effectiveness" should affect the conclusion that recommends "Everyone should use low-wattage bulbs". Shouldn't the recommendation be made based on facts rather than opinions? Whether current users think they are effective or not, without facts backing it up, it's just an opinion and should not change the conclusion.
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(0 votes)
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- Rose B. Green
  Posted 4 years ago. Direct link to Rose B. Green's post “First, just because somet...”
  First, just because something is a quantifiable fact, does not automatically make it relevant. Second, I am assuming you are proposing that D would be a better answer than B in the example above, since the other answer choices are more readily seen as helpful to evaluating the support. The conclusion of the argument is, "their [low wattage bulbs] advantages to the homeowner are enormous, and therefore everyone should use low-wattage bulbs". Answer choice B regarding the profits of bulb sellers is interesting, but irrelevant. For example, just because a drug seller may make profits from selling you a prescription, that does not in and of itself impact the efficacy of the prescription and the advantage that drug gives you. However, the conclusion is saying that all homes in should switch to the low wattage bulbs. What if many people are allergic to them? What if they break very easily and the glass gets everywhere? What if they had a bad smell? The list can go on... So, before we accept that EVERYONE should do something, I think feedback from initial users would be very useful. Hope that helps.
  Button navigates to signup page
  (6 votes)
malaktamer.abdou
Posted 4 years ago. Direct link to malaktamer.abdou's post “A decision is the most im...”
A decision is the most important thing in our life because it determines for us the next decision, and if a wrong decision is made , we must take responsibility for the decision.
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(1 vote)
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Josh Florek
Posted 6 years ago. Direct link to Josh Florek's post “I don't see any helpful t...”
I don't see any helpful to know questions under practice. Am I missing something?
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(0 votes)
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- Lindita Hajdari
  Posted 5 years ago. Direct link to Lindita Hajdari's post “I have had a couple of th...”
  I have had a couple of these question types come up under the advanced "Strengthen and Weaken" question sets under the Practice tab.
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  (2 votes)