Parallel reasoning questions
The ‘parallel reasoning’ questions are similar to the ‘method of reasoning’ questions in that you’re dealing with argument structure, and they’re similar to the ‘flaw in the reasoning’ questions in that many of the arguments that you’ll be presented with are going to be flawed. So, the content is always going to be an argument and these questions appear regularly but not frequently in every test. They tend to be relatively more difficult because of their length since in essence you’ll be dealing with six arguments. These questions basically ask you to replicate the structure of the argument in the passage and for the reasoning to be parallel the premises and the conclusion must match up between the passage and the correct choice. But the content of the argument doesn’t have to be the same and the sequence of the statements doesn’t have to be the same. There are several different wording variations:
“The reasoning in which of the following arguments is most similar to that in the argument above?”, “In which one of the following is the pattern of reasoning most parallel to that in the argument above?”, “The flawed pattern of reasoning in the argument above is most similar to that in which one of the following?”, “Which one of the following arguments contains an error of reasoning that is also contained in the argument above?”, etc.
For these questions the number and nature of the premises has to be the same, and they have to have the same relationship. The conclusion and the premises have to have the same relationship and the conclusion has to have the same scope and degree of probability. The validity or the flaw has to be the same (if the argument is flawed the question will always state that). There are a lot of different ways in which an argument can be structured so I’ll provide you with some basic categories that appear commonly, just like I did with the ‘flaw in the reasoning’ questions. But the basic approach when doing these questions is to have a good idea of the different broad categories of types of reasoning, and to have a good idea of how the premises support the conclusion. First, establish a clear picture of what the premises are and what the conclusion is and then determine what the structure of the argument is by looking at the relationships between the statements as well as keeping in mind the different variations we’re going to go over. And if it’s a flawed argument determine the ways that it’s flawed. Ok, so let’s take a look at some examples:
Conditional – If war is declared then we will either be invaded or we won’t be invaded. If we’re invaded we’ll put troops on the border, and if we’re not invaded we’ll prepare an aerial attack. So if war is declared we’ll either put troops on the border or prepare an aerial attack.
Ok, so this is an example of the conditional category of argument types. The first two sentences are the premises and the third sentence is the conclusion. The first premise presents a conditional statement where the necessary condition has two possible outcomes. The second premise is two additional conditionals where the necessary conditions from the first premise are used as sufficient conditions and additional necessary conditions are presented. So you’re basically just linking conditions: if A then B or notB, if B then C, if notB then D – therefore if A then C or D. The conditional statement arguments are going to have premises that are conditional statements or just the sufficient or necessary conditions by themselves, and the conclusions follow from the premises. And most of those arguments are going to be worded so that it’s obvious that you’re dealing with conditionals. So for this particular argument the correct answer choice is going to be the one that has the same structure. There are other variations, a common one is where not all of the premises are conditionals, for example there’s a conditional with a couple of necessary conditions and one of them is ruled out, leaving just one necessary condition. Likewise you’ll also find a broad group of conditional arguments where the conclusion isn’t a conditional, and those arguments will all have the general structure where the conclusion is what must follow given the premises. And in addition to the valid conditional arguments it’s a good idea to keep in mind some of the common ways in which conditional arguments are flawed. When it comes to the important basic elements, the valid and the flawed conditional arguments are more or less the same. But there are a couple of errors that routinely appear and that we’ve actually covered in the previous articles – the false negation, and the false reversal. So keep an eye out for those as you’re going through the conditional arguments.
Quality/Characteristic – Red apples are great for cider. These apples are yellow, so they won’t be as tasty for cider.
This is an example of the quality/characteristic argument type. The first sentence and the first part of the second sentence are the premises, and the second part of the second sentence is the conclusion. Yellow apples aren’t as tasty for cider as red apples because the red apples are great for cider. This category of arguments are going to deal with characteristics or qualities of groups or individuals and the relationships that arise between them. So as you’re going through the argument try and be on the lookout for any situations where the argument identifies an individual or group as having a particular characteristic, as in this case that red apples are great for cider. And then pay attention to how that characterization and that actor relate to other actors in the argument and any other characterizations that come up. Like here that yellow apples aren’t tasty for cider because they’re not red apples. This is an example of a common, and flawed, variation where a group is presented as having a certain characteristic and then another group is concluded not to have that characteristic because it’s not the same group. Another common flawed variation is where things that have characteristic X have characteristic Y and therefore things that have characteristic Y have characteristic X. Valid argument types will be analogies where shared characteristics show that different actors are related, where a situation conforms in some fundamental respects to another situation. Ok, so these arguments deal with the characteristics or qualities of different things and draw conclusions based on their relationships. The important thing with this argument type is to pay attention to the different actors in the argument, how they’re characterized, and how those characterizations are used to come to the conclusion.
JuiceCorp. has achieved spectacular sales this year either because of its bold marketing campaign or because of new juices. But JuiceCorp had an even bolder marketing campaign last year but didn’t have the same level of sales as this year so its sales are probably a result of its newer juices.
This is an example of the causality argument type. The first sentence and the first part of the second sentence are the premises and the second sentence is the conclusion. JuiceCorp’s sales are a result of its newer juices because it’s either a result of newer juices or bold marketing campaign and their marketing campaign was even bolder last year. Basically in this argument two things are presented as likely causes and one is ruled out so the other is determined to be the cause. As with the other categories for this question type we’ve gone over the basics for the ‘flaw in the reasoning’ question type and here we’ll first focus on the valid argument types. If you’re not told that the argument is flawed then you don’t have to critically evaluate it using the tools that we developed in the previous article for the arguments that involve causality; we just need to look to see if the premises, conclusion, and structure match up. In this particular example we concluded that one thing caused another because we ruled out another possible cause. This is a variation in the first broad category of causal arguments – where we conclude that one thing caused another. Another variation is where the premises say that two things have been linked together in a lot of previous cases and therefore one causes the other. You’ll also get variations where A doesn’t directly cause C but instead causes B which in turn causes C. The other broad category is where we conclude that one thing didn’t cause another. In these cases the premises point out that there’s a correlation between two things but that correlation doesn’t necessarily mean causation (it could be one of the things that we went over previously – maybe the cause and effect is reversed, maybe they’re both caused by something else, etc) and the conclusion concludes that there’s no causation. Ok, so the important thing is to pay attention to see in what way causal reasoning is used, whether the argument is making a claim that something is causally related to something else, that something isn’t causally related to something else, or whether the argument is flawed and employs one of the standard errors of causal reasoning.
The market share of laptops increased more than the market share of desktops from last year to this year. Therefore more people own laptops than desktops.
This is an example of the numerical argument type. The first sentence is the premise and the second sentence is the conclusion. More people own laptops than desktops because the market share of laptops increased more than the market share of desktops. Basically, these arguments are going to make a point that will require some sort of numerical reasoning – in general increase or decrease. In this case the argument is flawed because it talks about an increase in quantity in the premises, which is a relative change, but talks about an absolute amount in the conclusion. Maybe laptops had 5 percent of the market last year and they increased their market share to 10 percent, which is a hundred percent increase. And desktops went from having 95 percent of the market to 90 percent. So they decreased their share when laptops increased it, but does that mean that there are more laptops? No, there are still more desktops. The questions for this category are generally flawed arguments and this is a particular example of that. Another variation is where an increase in X means an increase in Y and therefore an increase in Y means an increase in X. This isn’t necessarily true, for example as a city’s population increases that means that pollution increases but that doesn’t mean that if pollution increases that means that the population increased. Maybe more polluting industries moved to the town. And another flawed variation is where the premises introduce statistics and probability but the conclusion isn’t warranted. For example: ‘the weatherman says there’s a 90% chance of rain but there’s no rain yet so it won’t rain today’. So when doing these questions pay attention to how the concepts of increase, decrease, and relative vs absolute values are used, along with percents and probability.
John intentionally gave his girlfriend a chocolate cake because it was her birthday. But they didn’t know she was allergic to chocolate and she ended up in the emergency room. So John intended to make his girlfriend sick.
This is an example of the shift category. The first two sentences are the premises and the last sentence is the conclusion. John intended to make his girlfriend sick because he gave her a cake that made her sick. The flaw is that the word ‘intentionally’ is used in a couple of different ways, it shifts from premise to conclusion. In the premises it’s used to show that John wanted to give his girlfriend a cake, and in the conclusion it’s used to conclude that he wanted to make her sick. But he didn’t know that she was allergic so he couldn’t have given it to her with the intent to make her sick. And that’s the basic structure of these arguments, as we went over in the previous articles arguments where there are shifts in terms what you need to make sure is to pay attention to what exactly the premises are talking about and what the conclusion is talking about and if there’s any disconnect between the two.
Ok, so as you saw, the important thing here is to have a good idea of what the argument is in the passage, what the premises and the conclusion are, and to have an idea of how the reasoning is structured. You do that by paying attention to the relationship between the statements. And then you have to repeat that process with each answer choice where it is above all crucial that you have a good idea of what the premises are and what the conclusion is. The point is to make sure that the reasoning structure is the same in the two arguments and as you look at each answer choice you should try and come up with a summary of the reasoning in the answer choice to compare it to the reasoning in the passage; as well you will need to pay attention to the premises in both arguments – to see if you have the same number of premises, the same kinds of premises, etc, and you will need to pay attention to the conclusion – to see if it’s the same kind of conclusion, and the validity. And as I’ve repeatedly mentioned, you shouldn’t look at all of these things separately and sequentially, instead it’s going to depend on the specific instance and of course in a lot of situations the reasoning structure is going to be different precisely because the premises or the conclusion is different.