It is not a good idea for farmers to grow genetically engineered crops. Studies that are critical of genetically engineered foods could be published, making the public even more wary of them. This leads to great financial risk, and the price at which the crops sell does not compensate for such risks.
Identify Conclusion
It is not a good idea for farmers to grow genetically engineered crops: “It is unwise for farmers to grow such crops.”
A
A farmer who grows genetically engineered crops on a large scale is taking a financial risk.
This is a sub-conclusion. It is supported by the premise that at any time a study could be published that would reduce consumers’ confidence in genetically engineered foods. The sub-conclusion in turn supports the conclusion that farmers are unwise to grow such crops.
B
It is not prudent for a farmer to grow genetically engineered crops.
This rephrases the conclusion.
C
The price paid for genetically engineered crops does not compensate for the financial risk farmers incur by growing them.
This is a premise: the rewards of growing genetically engineered crops do not outweigh the risks, which supports the conclusion that it is unwise for farmers to grow them.
D
A study could come out at any time that would greatly undermine public confidence in genetically engineered foods.
This is a premise. It supports the sub-conclusion that there is great financial risk associated with growing genetically engineered crops.
E
Consumers have very little confidence in genetically engineered foods.
This is a premise. Consumers having little confidence in genetically engineered foods supports the sub-conclusion that there is great financial risk associated with growing genetically engineered crops.
Summarize Argument: Phenomenon-Hypothesis
The author concludes that some residents switched to phosphate-free detergents. Her evidence is that phosphate pollution from the municipal water plant experienced a major decrease in the past year.
Notable Assumptions
Based on a mere correlation, the author assumes that the decrease in phosphate pollution from the municipal treatment plant was due to some residents switching to phosphate-free detergents. This means the author believes that such a switch can cause a “major decrease,” and that no other, unaccounted-for factor caused the pollution decrease.
A
Why did many residents continue to use detergents containing phosphates?
We don’t care why people continued using phosphate detergents. We need to evaluate the connection between the decrease in phosphate pollution from the treatment plant and some people switching to phosphate-free detergents.
B
What pollutants, if any, are present in phosphate-free dishwashing detergents?
We don’t care what pollutants are present. We’re simply evaluating the connection between the decrease in phosphate pollution from the treatment plant and some people switching to phosphate-free detergents.
C
Were any changes made in the past year to the way the municipality’s wastewater treatment plant treats phosphates?
If the answer to this is “yes,” then there may be some other factor that caused the drop in phosphate pollution from the local treatment plant besides people switching to phosphate-free detergents. If the answer is “no,” then a viable alternative cause is eliminated.
D
Does most of the phosphate pollution in the municipality’s waterways come from treated wastewater from the municipal treatment plant?
Irrelevant. We’re concerned with pollution from the municipal treatment plant. We don’t care where else phosphate pollution comes from.
E
Did municipal officials try to stop people from bringing detergents containing phosphates into the municipality?
We don’t care what official tried to do. We need to know if the decrease in phosphate pollution from the municipal treatment plant means that people switched to phosphate-free detergents.
Summary
Video games aren’t art. Why not? Because they’re interactive experiences. Art, meanwhile, must be an experience controlled by its creators. (Contrapositive: if it’s not controlled by its creators, it’s not art.)
Missing Connection
We know that something fails to be a work of art whenever it’s not controlled by its creators. But what does that have to do with video games? All we know about video games is that they’re interactive. Does being interactive mean the experience isn’t controlled by its creators? The author doesn’t say.
The conclusion would follow if we knew for sure that when an aesthetic experience is interactive, it’s not at all controlled by its creators.
The conclusion would follow if we knew for sure that when an aesthetic experience is interactive, it’s not at all controlled by its creators.
A
Most video game creators do not intend their video games to be works of art.
Intentions are irrelevant. None of the premises suggest that a creator’s intentions have any influence on whether something is art. Also, any assumption about “most” video game creators will be too weak to guarantee the conclusion that no video games are art.
B
An aesthetic experience cannot be both interactive and controlled by the artist or artists who created the work.
This says that if an aesthetic experience (such as a video game or work of art) is interactive, then it’s not controlled by its creators. We know that video games are interactive, so the conclusion now follows: video games aren’t controlled by their creators, so they’re not art.
C
For something to be a work of art, it must produce a rich aesthetic experience.
Contrapositive: if something doesn’t produce a rich aesthetic experience, it’s not art. But do all video games produce a rich aesthetic experience? We don’t know. So (C) doesn’t lead us to the conclusion.
D
Typically, video game players do not themselves create video games.
An assumption about what’s typical will be too weak to guarantee the conclusion that no video games are art. Also, whether or not a player also happens to create games tells us nothing about whether the things a player experiences are controlled by the game’s own creators.
E
Players’ choices that have no effect on the outcome of a video game are irrelevant to the aesthetic experience produced by that game.
What matters about a game’s aesthetic experience is whether it’s controlled by the game’s creators. (If not, then games aren’t art.) (E) doesn’t tell us anything about creator control. In fact, it doesn’t tell us anything that’s relevant to aesthetic experience at all.
Summarize Argument
The author concludes that if a piece sold as amber contains an insect that looks normal, it is more likely to be fake than if the amber doesn’t contain a normal-looking insect. The author supports the argument by establishing that forgers often add normal-looking insects to fake amber in order to make more money.
Notable Assumptions
The author assumes that real pieces sold as amber are not as likely to contain normal-appearing insects as are forged amber pieces.
A
Amber is often sold by small shops and street vendors that take few precautions to ensure authenticity.
This is irrelevant. The author is only making a claim about what characteristics make pieces more likely to be fake, a claim for which it doesn’t matter whether certain types of vendors are trying to ensure authenticity.
B
Pieces of amber that contain fossilized life forms are generally larger than plain pieces of amber.
The sizes of different pieces sold as amber are irrelevant to the author’s claim about what kinds of pieces are more likely to be fake based on the appearance of the insects inside.
C
Amber that contains insects usually demands a higher price than does amber that contains small plants.
The relative price of amber based on what type of life form it contains is irrelevant; the author is only making a claim about what kinds of pieces sold as insect-containing amber are more likely to be fake.
D
It is very difficult to distinguish between genuine and fake amber without destroying some of it.
This is irrelevant, since the author is not discussing the authenticity of pieces sold as amber based on the amber material itself, but rather based on the appearance of the insects embedded in pieces sold as amber.
E
Insects struggling to free themselves from tree resin are usually fossilized in awkward or grotesque positions.
This strengthens the argument by affirming the assumption that real pieces of amber are not likely to contain normal-looking insects, because they are instead likely to contain awkward- or grotesque-looking insects (if they contain insects at all).