### Calculate Price

Get a 10 % discount on an order above \$ 100
Use the following coupon code :
Whizz15

# Qualities of Explanations

An explanation is a statement that provides a reason for why or how something became the way it is. Arguments present a conclusion that’s presumably new to you and then support this conclusion with evidence that you’re likely to believe. Explanations work the other way around: they start with a conclusion that you likely believe (e.g., the sky is blue) and then offer an explanation for why that is so (e.g., because God is a UNC fan).

We will be looking specifically at causal explanations—that is, explanations in which you suggest that a particular physical or behavioral phenomenon is the result of another event.

 Situation Explanation Traffic on a Saturday There must be a football game today.

Most explanations start as theories. It can be challenging to fight the human impulse to pick the first theory that comes to mind and stop there, but what are the odds that the first thing you conceive of is in fact the best possible explanation?

 Situation Explanation Traffic on a Saturday Perhaps there’s a concert today? Maybe an art festival? Or possibly an accident up ahead?

With a little imagination, you can come up with a seemingly unlimited number of theories, but at some point you’ve likely exhausted all the plausible explanations.

 Situation Explanation Traffic on a Saturday Perhaps a new IKEA has been built without my hearing anything about it, and all these people are headed to the grand opening.

As with all critical thinking, you’ll need some judgment here. Discard the implausible theories (at least initially) and give fair consideration to all the reasonable ones:

• State your theory clearly (make a hypothesis).
• Consider possible alternatives.
• Look at the evidence.
• Evaluate the theory.

Sometimes the facts make the explanation quite clear:

I can see a train moving through an intersection several hundred yards ahead. That explains why traffic isn’t moving.

Other times, you’ll need to employ inductive reasoning to establish the most likely cause:

I can’t see the tracks from here, but I drive through here every Saturday morning and usually a train is responsible for traffic being stalled. So it’s probably a train.

We are presented with many such explanations on a daily basis.

Why are sales down for last quarter?
Why is my spouse not speaking to me?

As you consider potential explanations, keep the following standards in mind.

Consistency

First, is it internally consistent or does it contradict itself?

Second, is it externally consistent? Could this explanation effectively and fully account for whatever it’s supposed to explain?

A good theory should be compatible with what we already know about how the world works. This is a problem with many paranormal theories—they go against accepted scientific fact. If the theory contradicts established knowledge, the burden of proof is on the new theory.

Falsifiability

Life is fabulously convenient when there’s a quick and easy way to test a hypothesis. Simply asking an expert, examining the evidence, or swapping out the battery may be enough to validate or invalidate your hypothesis.

If you can’t test a theory, you’ve got a non-falsifiable hypothesis because there’s no theoretical way to prove it false.

The lucky rabbit’s foot brings good luck every time the energy in the air is good.

The reason the weather has been getting hotter is because Hephaestus, the ancient Greek god of fire, is angry that people don’t believe in him anymore.

A fortune teller predicts that a stranger will have a profound influence on your future in ways you don’t even realize.

Scope

Great explanations have broad predictive power—they explain a lot. The more the theory predicts and explains, the better. This was how the heliocentric theory ultimately won out over the geocentric theory; the proposition that the earth moves around the sun explained so much more in astronomy than the proposition that the sun moves around the earth.

Simplicity

As a general rule, the best explanation is the simplest one that makes the fewest assumptions. Check out any conspiracy theory. These theories tend to involve unnecessarily complex explanations that raise more questions than they answer, as opposed to mainstream explanations, which are typically simpler and based on plausible premises.

Causality

Just because two things often happen together (correlation), this doesn’t necessarily mean that one causes the other.

Peter’s baby teeth began to fall out around the same time he got better at riding a bike without training wheels. Therefore, Peter’s bike-riding skills were improved by his teeth loss.

There’s no reasonable link between teeth falling out (the purported cause) and bike-riding ability (the purported effect) for this to be a good explanation.

• Response Board Question

Top of Form

Imagine that you go into your home and see muddy footprints on the floor from shoes you know are not your own. Give examples of two plausible explanations and two unlikely explanations for the footprints.

Which of the following explanations for a sudden increase in car accidents at a particular intersection is an unfalsifiable hypothesis?

• Drivers going through the intersection are experiencing a secret impulse to drive recklessly.
• A popular new nightclub has opened two blocks away, leading to more impaired drivers in the neighborhood.
• The new mall built nearby has drawn more young, inexperienced drivers to the area.
• Road conditions have worsened due to an unusually cold and wet winter.

Multiple Choice Question

Tyler and Grace water their amaryllis plant regularly, yet for some reason the plant withers and dies. Tyler suggests, “Maybe there was some peculiar property of this particular amaryllis that caused water molecules to react with the soil molecules and chemically change into arsenic molecules, and the arsenic poisoned the plant.” Which of the following is one of the drawbacks of Tyler’s proposed explanation?

• It is consistent with what science knows about chemical reactions involving water molecules.
• It contradicts itself by claiming that water both helped the plant and hurt the plant at the same time.
• It is too simple and doesn’t make enough assumptions about how water molecules behave.
• It confuses correlation and causation by assuming that watering the plant had something to do with its death.

Bottom of Form

# Practice: Qualities of Explanations

## Explaining an Epidemic

Sometimes we seek valid explanations for events merely to satisfy our own personal curiosity, such as wondering why a new mural on the side of a building downtown suddenly appeared. Other times, finding an explanation can be literally a matter of life and death. The following two videos recount the tragedies of the London cholera outbreak of 1854 and physician John Snow’s heroic quest to find, quite simply, an explanation.

YouTube video. https://youtu.be/HKA0htesJOA. Uploaded May 2, 2012, by the U.S. Census Bureau. To activate captions, first click the play button and then click the CC button in the embedded player. For a text transcript, follow the link below.

TED video. http://www.ted.com/talks/steven_johnson_tours_the_ghost_map. Filmed November 2006 at TEDSalon 2006. To activate subtitles, first click the play button and then open the dropdown menu in the embedded player and choose a language. For a text transcript, follow the link below.

In the situation presented in the first video, what was in need of an explanation?

• what caused the bad smells in London
• what caused the cholera outbreak
• why England had more epidemics than other countries
• why cholera was so much more dangerous than other diseases

According to the “Answering the Three Questions” video, in what way was the “miasmas” (bad smells) explanation inconsistent?

What explanation did Dr. Snow settle on?

• Cholera spread through contaminated food.
• Cholera spread through the water supply.
• Cholera spread through contaminated air.
• Cholera spread from animals to people.

How was Dr. Snow able to test his proposed explanation?

Explain how Dr. Snow was able to demonstrate that he wasn’t confusing correlation with causation.

Good explanations are often simple, yet they can explain a lot. Explain how the story of Dr. Snow’s “ghost map” drawing demonstrates this.

Steven Johnson argues that the story of the cholera epidemic and Dr. Snow’s map is “fundamentally optimistic.” Explain whether or not you agree and why.

# Scientific Explanations

Science is all about explanations, about understanding how the world works and finding ever better ways to explain and manage it. As such, scientists tend to excel at critical thinking, and they typically have higher standards for explanations than those in other walks of life.

### Science Basics

• Science is a means for uncovering truth that investigates causal explanations to discover empirical facts about how the world works.
• Science is not the only way of constructing knowledge, since we also learn about the world from direct perception, by reasoning, and through aspects of life that are not empirically measurable, such as humor, dignity, and love.
• The reliability of science comes from its use of precise definitions, clearly defined contexts, and replicable results. If no one else can recreate your experiment, it’s more anecdote than science.

It is worth noting that while scientific investigations produce verifiable insights, they also routinely invalidate the results of earlier scientific investigations. For this reason, scientists must remain vigilant for errors in method, measure, or inference and be open to alternate explanations.

### The Scientific Method

Science is defined by a particular mode of investigation that scientists follow to investigate causal claims. This is known as the scientific method, and it involves a series of steps:

1. Identify the problem or question.
2. Gather evidence and make observations.
3. Form a hypothesis to explain what is happening.
4. Perform an experiment to test the hypothesis.
5. Analyze the results to see if they confirm or refute the hypothesis.

This structure is consistent with much of critical thinking. What sets scientific claims apart are their empirical, observable data and the replicability of experiments.

Bear in mind that research methodology is a rich and complex discipline because there are so many ways for an experiment to go wrong or provide misleading evidence. The basics of the scientific method are quite simple, but executing valid experiments and reasoning soundly from good data isn’t nearly as straightforward as it may seem.

### Limits of Science

Science provides such compelling evidence for claims that it’s worth mentioning a few of the limitations of science.

#### Bias

Scientific efforts may be undertaken by people with personal, political, or financial motives pushing them into many of the pitfalls we’ve previously described, such as selection bias in choosing what to test, how to structure the test, and which evidence to share. Another common failing is to conclude the overall experiment with an explanation that conveniently supports the scientist’s goals but isn’t the best explanation possible.

#### Metaphysics

Science can’t explain things that can’t be observed and measured. So questions of ethics, aesthetics, and metaphysics are usually outside the scope of the scientific method. For example, the scientific method is, ironically, insufficient for making an argument that science is valuable.

#### Science vs. Pseudoscience

Some claims look like science but aren’t. We call these pseudoscience. Pseudoscience doesn’t follow the rules of the scientific method. To protect yourself from being taken in by pseudoscience, look out for the following signs:

• Providing the explanation after the fact
• Failing to consider alternatives
• Not being open to the possibility of error
• Bypassing peer review before reporting widely
• Relying heavily on anecdotal evidence

A pseudoscientific explanation will often fail many of the standards of a good explanation in the following ways:

• Not empirically testable
• Doesn’t explain anything beyond the phenomenon it’s supposed to explain
• Overly complex / raises more questions
• Doesn’t fit in with what we already know about how the world works

Multiple Choice Question

Which of the following questions would you MOST likely look to science to answer?

• Will passing legislation limiting air pollution antagonize voters who oppose government regulation?
• Are there any circumstances in which humans can telepathically communicate with one another?
• Will life be more fulfilling if you devote it to the pursuit of meaningful interpersonal relationships or to the work of making the world a better place?
• Did Percy Shelley’s poetry have more influence on English Romanticism than Lord Byron’s?

Multiple Choice Question

Which of the following is an accurate statement about the nature of science?

• Science avoids considering alternate explanations or being open to the possibility of error.
• Science relies heavily on anecdotal evidence.
• Science is self-correcting and perpetually seeking out the best and most accurate explanations.
• Science is the only way we construct knowledge.

A friend claims that eating chocolate can strengthen your bone marrow. You’re skeptical of the credibility of that statement, so you read two scientific studies. The first, funded by a large chocolate manufacturing company, confirms this assertion, while the second, funded by the American Society for Nutrition, reaches the opposite conclusion. Should you be more inclined to trust one of these reports over the other? Explain your answer.

# Practice: Scientific Explanations

## Full Moon, Weird Things

With all the strange and miraculous things going on in the world, sometimes the most astonishing and seemingly impossible claims turn out to be completely true. Other times, they’re not. How can you tell the difference? In the first video below, Michael Shermer, editor in chief of Skeptic magazine, provides a list of ten questions you should ask yourself whenever you’re presented with a claim that may be scientific or pseudoscientific. The second video, also featuring Michael Shermer, explores the veracity of the popular notion that strange things happen when the moon is full.

Watch the video below, and then answer the following questions.

YouTube video. https://youtu.be/hJmRbSX8Rqo. Uploaded September 5, 2012, by Rob Robbie. To activate captions, first click the play button and then click the CC button in the embedded player. For a text transcript, follow the link below.

According to Shermer, why do people believe in “weird things”?

• Only scientists are capable of sorting out truth from falsehood.
• Our brains are wired to find meaningful patterns.
• People fail to realize that they should only believe what they can see with their own eyes.
• Our nation’s educational system fails to adequately teach the difference between science and pseudoscience.

Multiple Choice Question

One of the examples of bad science in the video is the story of the Fleischmann-Pons cold fusion experiment. What was the problem with the cold fusion claim?

• No one else could replicate the experiment.
• Fleischmann and Pons lacked scientific backgrounds.
• The media misrepresented their claims.
• There was no practical use for cold fusion.

Multiple Choice Question

According to Shermer, what is the difference between the people at SETI and people who believe in UFOs?

• People who believe in UFOs are idiots.
• People who believe in UFOs have a preponderance of evidence.
• The SETI people are playing by the rules of science.
• The SETI people use a lot of high-tech equipment.

Watch the video below, and then answer the following questions.

YouTube video. https://youtu.be/KoyDmwNwIKQ. Uploaded October 19, 2009, by TARPSociety. To activate captions, first click the play button and then click the CC button in the embedded player. For a text transcript, follow the link below.

One of the nurses says, “I’m a nurse, and I know this for a fact.” Explain how this comment could be used to illustrate the fallacy of unqualified authority.

Point 5 in the Baloney Detection Kit asks whether anyone has tried to disprove this claim. What does the video suggest regarding this point?

Point 6 in the Baloney Detection Kit asks where the preponderance of evidence seems to point. While this video depicts conflicting claims, it suggests that most of the evidence supports which side?

In the flashback to the 1984 news report, the newscaster references a study conducted by a Florida researcher that demonstrated that more murders were committed during a full moon; Shermer then reveals that the study proved to be flawed. Using one of the elements of good vs. bad science detailed above, offer a theory as to what might have gone wrong in this scientific study.

Statistics and Fallacies

Referring to a patron by name will increase tips by 18 percent.

Statistics suggest a precision and certainty that is not always warranted. Derived from gathering and analyzing data, statistics usually involve making a calculation and generating a result in a way that superficially resembles a math problem, which implies that the answer is as certain as the truth that 2 + 2 = 4.

But statistical claims are rarely worthy of this level of confidence, and as critical thinkers we need to look closely at how the data were gathered and analyzed. Below are some common problems to watch out for.

Small Sample Size

Only 33 percent of nine-year-olds watch Arthur. I know because I asked three nine-year-olds if they watch Arthur, and just one of them said yes.

While it is technically true that one out of three is 33 percent, it would be deceptive to suggest that this statistic can be generalized broadly when the sample size is far too small to be representative of the entire population of nine-year-olds.

Biased Sample

According to my research, 72 percent of Americans are pulling for the Carolina Panthers. I know because I conducted a scientifically valid survey in Charlotte, North Carolina.

If the sample group surveyed isn’t representative of the population at large in relevant ways, it would be misleading to apply this statistic to Americans in general.

Manipulative Survey Questions

Approximately 89 percent of Americans are in favor of federal healthcare. I know because we conducted a scientifically valid survey from a random sample of American households, controlling for 15 demographic variables. In each survey we asked, “Would you prefer healthcare costs to rise while quality drops, or would you prefer federal healthcare?”

Even if you know that a large and diverse pool of people have been surveyed, if the wording of the question was ambiguous or loaded, the reported statistic may be worthless.

Statistics Based on Guesswork

College students average 4.2 hours of study for every hour in class, according to a study in which the participants were asked about their study habits.

This problem plagues any study relying on the self-reporting of participants without verification. Such studies assume that people will always answer truthfully even when their answers might implicate them as unethical, dishonest, criminal, or engaged in thoughts or actions that flout cultural norms.

Missing Background Information

In the five years since the city built the new bike paths, the annual total of bicycle accidents on the main roads has dropped by 34 percent.

Are we talking about 150 bicycle accidents reduced to 100? Or more like three accidents reduced to two? Without any background information beyond the statistic, it’s hard to truly evaluate the impact the new bike paths may have had.

Multiple Choice Question

Sharlene is supposed to poll people about their voting choices for her American Government class. She asks four random people on the street about their vote and then reports to her class that 75 percent of the city voted Republican. What is the MOST obvious problem with her statistic?

• The sample size is too small.
• The statistics are based on guesswork.
• Background information is missing.
• The survey question is manipulative.

Multiple Choice Question

To find out if members of the community are opposed to soft drinks being sold in middle school cafeterias, Gregoire conducts a survey asking, “Do you support the practice of schools pushing the sales of substances known to lead to obesity and heart disease onto impressionable minors?” After analyzing the results, he concludes that 78 percent of people oppose the sale of soft drinks. What is the problem with his statistic?

• The sample size is too small.
• The survey question is manipulative.
• Background information is missing.
• The sample is biased.

Response Board Question

Top of Form

Imagine that you run across a statistic online claiming that men are 25 percent more likely to ski on dangerous slopes than women. Give examples of at least two pieces of information you would want to know about this statistic before you would accept it as fact.

# Practice: Statistics and Fallacies

## Is a Law Degree a Ticket to Wealth?

Some statistics are deliberately twisted and manipulated, and some are complete fabrications. But even when a statistic comes from a legitimate academic study and has no obvious problems regarding sample size, bias, or manipulative wording, it doesn’t mean that your work as a critical thinker is finished. In the following blog post, Burt Likko analyzes a statistic reported by professors Michael Simkovic and Frank McIntyre in their paper “The Economic Value of a Law Degree” and questions exactly how much value we can place on it.

Deception with Statistics

Multiple Choice Question

In the scenario the writer describes in the beginning, what are law students most concerned about?

• whether they will have high levels of student debt
• whether they will be accepted into a prestigious law school
• whether they will get well-paying jobs after they graduate
• whether they will pass the bar exam

Multiple Choice Question

The writer discusses a statistic about the economic value of a law degree. Which types of people would MOST likely have a personal investment in accurately understanding this statistic?

• people who used to work in law but have now switched professions
• people who haven’t previously considered going to law school
• people who are evaluating whether going to law school will be financially worth it
• people who hope to teach at a law school

Multiple Choice Question

The study analyzed by the writer arrived at which of the following conclusions?

• All graduates of the most prestigious law schools earn \$1,000,000 in their lifetimes.
• On average, people with law degrees will earn \$1,000,000 in their lifetimes.

Multiple Choice Question

The writer criticizes Simkovic and McIntyre’s paper because it “fails to include some other big numbers.” What “big numbers” does the statistic avoid addressing?

• the difference between earnings in the 25th, 50th, and 75th percentiles
• the costs of going to law school
• the income difference between men and women

Multiple Choice Question

What does the writer mean when he says, “There’s a long tail that comes after the tall head”?

• Law-school graduates usually have to wait a long time before they can get a job in their field.
• There is a small number of law-school graduates who make very high salaries, but there is a far larger number of law-school graduates who make significantly lower salaries.
• The huge expense of going to law school will be followed by long years of solid income to make up for it.
• Law-school graduates have many long years of paying back student loans after their three years of law school.

Response Board Question

Now that you’ve read the writer’s evaluation of the claim that “the mean pre-tax lifetime value of a law degree [is] approximately \$1,000,000,” explain whether or not you think that statistic qualifies as “deceptive” and why.

Imagine that you’re considering going back to school for an MBA and trying to evaluate whether the investment of time and money will be worth it. You read on this website that, according to the 2012 Alumni Perspectives Survey of the Graduate Management Admission Council (GMAC), “the median annual salary for MBA degree-holders was \$95,000 with additional compensation (bonuses, etc.) of \$18,123 annually.” Provide at least two questions you would want to ask about this statistic before accepting it as fact.

Get a 10 % discount on an order above \$ 100
Use the following coupon code :
Whizz15

Category: Sample Questions