Part 4 (2/2)
Evidence: The evidence includes any facts, examples, statistics, surveys, and other information or data that the author (writer or speaker) uses in support of his or her conclusion.
a.s.sumption: The a.s.sumption is the authoras unstated belief (aunstated evidencea) about why his or her claim is right. An a.s.sumption is that part of the argument that the author, writer, or speaker a.s.sumes to be correct without stating so; it is athat which the author takes for granted.a More poetically, the a.s.sumption may be said to be athe glue that holds the evidence to the conclusion.a THE ABCs OF ARGUMENT STRUCTURE Tip #20: Evidence + a.s.sumption = Conclusion. The a.s.sumption is the glue that holds the evidence to the conclusion.
The following expresses the relations.h.i.+p between the three elements of cla.s.sic argument structure: Conclusion = Evidence + a.s.sumption or Conclusion a' Evidence = a.s.sumption The ability to understand simple but formal argument structure is useful, if not essential, to advance critical thinking. After identifying the conclusion and evidence, we then proceed to examine the third element, called the a.s.sumption. So how do we go about identifying the first two elements, the conclusion and evidence?
Identifying the Conclusion and Evidence Confusion may arise as to what part of an argument is evidence and what part is the conclusion. Certain ”guide words” always signal the use of evidence or the start of the conclusion. The chart on the next page lists the most common guide words. If, for example, you hear someone say, aBecause the economy is getting better, Iam going to buy a car,a you may presume that the phrase abecause the economy is getting bettera is evidence. The reason for this is that abecausea always signals the use of evidence. The remaining phrase aIam going to buy a cara contains the conclusion. Note that these phrases may also be reversed without affecting what is the evidence and conclusion. For example, aIam going to buy a car because the economy is getting better.a If possible, use guide words to identify the conclusion and evidence in an argument.
It is important to note that guide words will not always be present to guide you, meaning that you cannot always rely on them to locate the conclusion and the evidence in an argument.
Locating the a.s.sumption Whereas the conclusion and evidence in an argument are always explicit, the a.s.sumption is always implicit. The fact that a.s.sumptions are by definition implicit means that they will not be stated, that is, written down on paper or spoken out loud by the speaker. They exist foremost in the mind of the author or speaker. Conclusions and evidence, on the other hand, are explicit. This means that they will be stated a” physically written down on paper or spoken out loud.
EVALUATING ARGUMENTS.
Tip #21: There are effectively two ways to attack an argument: attack the evidence or the a.s.sumption(s).
In seeking to evaluate arguments, we must aggressively a.n.a.lyze each component. How strong is the evidence? How strong is the key a.s.sumption? Obviously, in order to attack the evidence and the a.s.sumption, we must be able to identify them.
Short exercises: To practice using cla.s.sic argument structure to evaluate arguments, fill in the missing pieces below a” conclusion, evidence, and a.s.sumption. Proposed solutions follow below.
1. Dorothy and her College Entrance Exam Argument: As Dorothy achieved a high score on her college entrance exam, she will surely succeed in college.
Conclusion: Evidence: a.s.sumption: 2. Finland Argument: Finland is the most technologically advanced country in the world. More people per capita own mobile phones in Finland than anywhere else on earth.
Conclusion: Evidence: a.s.sumption: 3. Taking on the World with a Smile Argument: Dear Anita: You know, I get such a great feeling when I talk to my old high school friends and find out theyare doing well. Just yesterday, I spoke with Paul and Maxine and have been in a good mood ever since. Say, I hear youare kind of down in the dumps lately. If you go home and call your high school friends, it will cheer you up and you will be ready to take on the world with a smile. Talk to you soon, Bill.
Conclusion: Evidence: a.s.sumption: 4. Quick-Stop vs. Big-Buy Grocery Stores Argument: I shop at Big-Buy grocery stores because prices are 10% less than at Quick-Stop grocery stores.
Conclusion: Evidence: a.s.sumption: 1. Dorothy and her College Entrance Exam (Solution) Argument: As Dorothy achieved a high score on her college entrance exam, she will surely succeed in college.
Conclusion: Dorothy will surely succeed in college.
Evidence: She achieved a high score on her college entrance exam.
a.s.sumption: Success on a college entrance exam leads to success in college or, stated another way, success in college requires the same set of skills as is required to perform well on a college entrance exam.
Letas evaluate the argument.
Attack the evidence Did Dorothy really score high on her college entrance exam? How high is high? In other words, we need to find out what score she actually got and then verify that it was indeed a ahigha score.
Attack the a.s.sumption This argument a.s.sumes that a high test score is not only enough to get accepted to college in the first place, but also that itas a good predictor of success in college. First, the college admissions process also considers other factors, including a candidateas written application essays, extracurricular activities, personal/academic references, and even an interview. Second, other factors that are likely required for success in college are not related to taking a test. Succeeding on a test requires no interaction with anyone except oneself. What about other factors, such as personal motivation, independence, or emotional stability? Some courses may require group projects. In short, Dorothy may not have the personal qualities to succeed in college, even though sheas mighty fine at taking an entrance exam!
2. Finland (Solution) Argument: Finland is the most technologically advanced country in the world. More people per capita own mobile phones in Finland than anywhere else on earth.
Conclusion: Finland is the most technologically advanced country in the world.
Evidence: More people per capita own mobile phones in Finland than anywhere else on earth.
a.s.sumption: Owners.h.i.+p of mobile phones is the best criterion for determining whether a country (or its people) is technologically advanced.
Letas evaluate this argument.
Attack the evidence Even though people own phones, do they actually use them? Do they know how to use the vast majority of all the phone functions? Also, are mobile phones as technologically sophisticated in Finland as they are in other countries?
Attack the a.s.sumption Perhaps owners.h.i.+p of mobile phones (per capita) is not the best criterion for determining technological advancement. Perhaps a better, more accurate criterion is owners.h.i.+p of computers or the ability to use computer software. Or perhaps the best criterion for determining technological advancement is the ability to manufacture technologically advanced equipment.
3. Taking on the World with a Smile (Solution) Argument: Dear Anita: You know, I get such a great feeling when I talk to my old high school friends and find out theyare doing well. Just yesterday, I spoke with Paul and Maxine and have been in a good mood ever since. Say, I hear youare kind of down in the dumps lately. If you go home and call your high school friends, it will cheer you up and you will be ready to take on the world with a smile. Talk to you soon, Bill.
Conclusion: If you go home and call your high school friends, it will cheer you up and you will be ready to take on the world with a smile.
Evidence: You know, I get such a great feeling when I talk to my old high school friends and find out theyare doing well. Just yesterday, I spoke with Paul and Maxine and have been in a good mood ever since. Say, I hear youare kind of down in the dumps lately.
a.s.sumption: In the same way that calling his high school friends aworksa for Bill, it will also aworka for Anita.
Again, there are two ways to attack this argument: Attack the evidence Is Anita really feeling down? Are Billas buddies actually doing well? Are Paul and Maxine actually the high school cla.s.smates of Bill?
Attack the a.s.sumption Does Anita have high school friends? Are they also doing well? Upon hearing that Anitaas high school friends are doing well, will she react as favorably as Bill did (hopefully Anitaas not the jealous type)?
4. Quick-Stop vs. Big-Buy Grocery Stores (Solution) Argument: I shop at Big-Buy grocery stores because prices are 10% less than at Quick-Stop grocery stores.
Conclusion: I shop at Big-Buy grocery stores.
Evidence: Prices are 10% less.
a.s.sumption: Price is the decisive factor in determining where I shop for groceries. Or stated more simply, when choosing between Big-Buy and Quick-Stop, I choose based on price.
Letas attack the argument: Attack the evidence Are prices really 10% less at Big-Buy grocery stores? Are prices even cheaper at all? We need proof. Perhaps itas time to check grocery receipts to verify claims of lower prices. Donat just take for granted that all evidence is really agooda evidence. Moreover, is quality constant? If the quality of two items is different, better quality might warrant paying higher prices.
Attack the a.s.sumption For example, we may want to attack the a.s.sumption by saying that price should not be the motivating factor as to where we shop. Perhaps location or proximity is a better criterion, or perhaps customer service should be the key factor influencing where we shop; perhaps store appearance and cleanliness should be the determining factor; perhaps prestige is the driving factor.
THE FIVE COMMON REASONING FLAWS.
Tip #22: The five most common critical reasoning errors include: comparing aapples with oranges,a over-generalizing on the basis of small samples, ignoring relevant evidence, confusing cause and effect, and failing to antic.i.p.ate bottlenecks when plans are put into action.
When we speak of critical reasoning errors, we are referring largely to errors relating to the a.s.sumptions we make. Of the five common types of a.s.sumptions, the first category falls under comparison and a.n.a.logy a.s.sumptions and requires that we compare two things which, although different, are logically equivalent. In general, we want to compare apples with apples and oranges with oranges, without mixing the two. The second category falls under representativeness a.s.sumptions. This reasoning error involves overgeneralizing on the basis of small samples or limited experience. In making the a.s.sumption that a sample is representative of the larger whole, we strengthen an argument. In making the a.s.sumption that the sample is not representative of the larger whole, the overall argument is weakened. The third category falls under agood evidencea a.s.sumptions. This reasoning error occurs when we take for granted that the evidence chosen is valid. The a.s.sumption that evidence chosen is objective, typical, and truthful serves to strengthen any argument; the idea that evidence chosen is subjective, atypical, or spurious serves to weaken any argument. The fourth category falls within the topic of cause-and-effect a.s.sumptions. This reasoning error occurs if we mistakenly match cause with effect, or a.s.sume, without adequate evidence, that one event is the cause of another. The fifth category falls under implementation a.s.sumptions. This reasoning error arises from not antic.i.p.ating bottlenecks when plans are put into action, and occurs whenever we a.s.sume outright that plans can be turned into action without significant impediments.
Comparison and a.n.a.logy a.s.sumptions We make comparisons based on people, places, things, or situations. Often it is done through a.n.a.logy. What is an a.n.a.logy? An a.n.a.logy is a comparison of two (or more) items made on the basis that because they share one or more similarities, we can therefore a.s.sume they are alike in one or more other respects. An a.n.a.logy is created every time a researcher delves into the realm of biological experimentation and compares the results done on animals, usually mice, to human beings. Sometimes, the comparison involves personal characteristics. We may see certain traits or characteristics in a father and son or mother and daughter and believe it is the basis for their sharing other similar characteristics. Other times, the comparison involves comparing two situations or events over different time periods. Many corporate decisions are still based on the idea that what has worked in the past will work in the future. International law is also, in large part, based on the principle of historical precedent.
The general strategy for attack is as follows: In terms of evaluating or attacking comparisons, when two things are deemed similar, our goal will be to find dissimilarities in order to show that the two things are not alike. Consider the following example: aMartha did such a great job selling cutlery that weare going to promote her and put her in charge of condominium sales.a What is being a.s.sumed is that sales ability is the key ingredient in making sales, and the type of product being sold is of secondary concern. How could we attack this argument? One way is to indicate that there could be a big difference between selling cutlery, a commodity product, and selling a condominium, a luxury good. A person effective at selling one type of product may be ineffective when selling another type. In the entrepreneurial context, a person successful in one industry may not be successful when switching to another industry.
In terms of evaluating or attacking comparisons, when two things are deemed dissimilar, our goal will be to find similarities in order to show that the two things are alike. For example, two male sports enthusiasts are having a beer, when one says to the other: aThere is no comparison between athletes today and athletes of yesteryear. Mark Spitz won seven gold medals in swimming in the 1967 Mexico City Olympics, but his winning times are not good enough today to qualify for any of the menas Olympic swim events.a To damage this argument, the second sports enthusiast might want to choose an example to show how athletes today are in some ways comparable to the athletes of yesteryear. For example, Jack Nicklausa final round score of 271 in 1965 to win the Masteras Golf Tournament in Augusta, Georgia, could be compared to Tiger Woodsas final round score of 272 in 2002 to win the Masteras Golf tournament on the exact same course. In this respect, by comparing two athletes in this manner, things do not look so dissimilar after all.
When comparing two things, particularly those across different time frames, we must be careful not to a.s.sume that information gathering techniques and, therefore, the quality of the data obtained are comparable. For example, any report comparing the findings of worker satisfaction levels in the 1940s to worker satisfaction levels today would be suspect, for no other reason than the difficulty of comparing the results of information gained under differing circ.u.mstances.
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