Critical Thinking 1
Dona Warren
Slide 1 Hello, I’m Dona Warren, and I’d like to talk a bit about critical thinking in the classroom.
Slide 2 This is a subject worth discussing because although critical thinking skills are often listed
among the suggested or required learning outcomes for a course, there’s sometimes a
frustrating confusion and vagueness about what exactly these critical thinking skills are.
Slide 3 The literature on this subject is vast and competing, but there are many point of
agreement. We can safely say that critical thinking skills help us to evaluate the acceptability of
claims through assessing the sources of the claims or analyzing and evaluating the arguments
(chains of reasoning) in support of the claims, that critical thinking skills help us to discover new
acceptable claims by engaging in scientific reasoning or constructing arguments, and that critical
thinking skills can help us to demonstrate to someone else that a claim is acceptable (or
unacceptable) by effectively communicating arguments.
It’s important to realize that many important activities and skills - like simply believing
claims that put presented to us (which we have to do most of the time), exercising creativity or
intuition, and engaging in various kinds of non-persuasive communication - fall outside the
scope of critical thinking.
Slide 4 We can recognize that critical thinking is important without thinking that it’s the only
important thing and so a well-rounded set of learning outcomes for most courses will contain
knowledge, skills, and dispositions other than those associated with critical thinking.
Furthermore, there are too many critical thinking skills to conceivably cover them all in any
single course. The thing to do is identify the critical thinking skills that you think are the most
important to your students, and to focus on those.
Slide 5 To give you a sense of some of the skills that you might want to incorporate into your
course, let’s look at the four broad skill sets that I try to address in my own class on critical
thinking: argument recognition, analysis, evaluation, and construction.
Slide 6 Argument recognition involves determining that a passage attempts to establish the
acceptability of one claim by citing other ideas as evidence.
Slide 7 Argument analysis – the most complex of these four skills sets – involves distinguishing
between important and unimportant ideas and understanding how the important ideas work
together to establish the acceptability of the ultimate conclusion of the argument.
Slide 8 Argument evaluation involves evaluating the premises (or the ideas that are being taken
for granted), evaluating the inferences (or the connection between ideas), and understanding
what bearing the argument has upon the ultimate conclusion.
Slide 9 Argument construction involves asking a question, researching possible answers, settling
upon a position, and attempting to defend that position by constructing a strong argument to
support it.
Critical Thinking 2
Dona Warren
Slide 10 We can see how recognizing an argument works by consider this example passage:
“Critical thinking is all the rage today, and chances are good that you think critical thinking skills
should be integrated into general education courses. Well, you’re wrong. We shouldn’t try to
explicitly teach critical thinking skills in our general education courses. For one thing, critical
thinking skills are inextricably discipline-specific. This means that they aren’t generalizable, and
general education courses should focus on generalizable skills. For another thing, general
education courses should teach facts, not how to think. And finally, most of our students will
acquire their critical thinking skills without explicit instruction because most of us acquired our
own critical thinking skills that way.” This passage does contain an argument because it presents
us with a unit of reasoning that attempts to establish that an idea is acceptable by citing other
ideas as evidence.
Pre-Post test results from spring of 2006 through spring 2009 (with 461 students taking
the pre-test and 442 taking the post-test) indicate that before taking a critical thinking class
(Philosophy 121), 67.46% of students are confidently able to correctly identify a passage as
containing an argument. After taking a critical thinking class, 89.4% of students are confidently
able to correctly identify a passage as containing an argument.
Slide 11 When we analyze an argument, I try to help my students to see how the argument
works by teaching them to identify the ultimate conclusion first (in this case the claim that we
shouldn’t try to explicitly teach critical thinking skills in our general education courses), to
recognize that an idea is important only if it helps to establish the truth of the ultimate
conclusion (which makes the first two sentences in this passage unimportant) and to
understand how the ideas advanced in support of the ultimate conclusion work together to
establish the ultimate conclusion. In order to understand the patterns of cooperation between
these ideas, I urge my students to take advantage of special expressions, including themechangers like “for one thing,” “for another thing,” and “finally,” inference indicators like “this
means that” and “because,” and inference erasers like “and.”
The Pre-Post test results indicate that before taking a critical thinking class, 80.91% of
students are confidently able to correctly identify the ultimate conclusion of an argument. After
taking a critical thinking class, 92.8% of students are confidently able to correctly identify the
ultimate conclusion of an argument.
Before taking a critical thinking class, 42.08% of students are confidently able to
recognize unimportant ideas. After taking a critical thinking class, 81.7% of students are
confidently able to recognize unimportant ideas.
Slide 12 Once students understand how the ideas advanced in support of the ultimate
conclusion work together to establish the ultimate conclusion, they can diagram the argument
like so. This is a very handy way to represent an argument because it clearly displays the
structure of the reasoning and makes clear the role played by each idea in the argument.
Premises are taken for granted by the argument. Subconclusions are supported by other ideas.
And the ultimate conclusion is the main idea that the argument attempts to establish. An
inference is the connection that holds between two ideas when the truth of one allegedly
Critical Thinking 3
Dona Warren
establishes the truth of the other. Dependent reasons need to work together to establish an
idea. Independent reasons can establish an idea on their own.
The Pre-Post test results indicate that before taking a critical thinking class, 80.91% of
students are confidently able to correctly identify the ultimate conclusion of an argument. After
taking a critical thinking class, 92.8% of students are confidently able to correctly identify the
ultimate conclusion of an argument.
Before taking a critical thinking class, 52.71% of students are confidently able to identify
an idea as a premise. After taking a critical thinking class, 74% of students are confidently able
to identify an idea as a premise.
Before taking a critical thinking class, 17.79% of students are confidently able to identify
an idea as a subconclusion before taking a critical thinking class. After taking a critical thinking
class, 66.7% of students are confidently able to identify an idea as a subconclusion.
Before taking a critical thinking class, 73.53% of students are confidently able to
correctly identify the inferential relationship between two ideas when the inference is indicated
with conclusion indicator like “therefore.” After taking a critical thinking class, 84.2% of students
are confidently able to correctly identify the inferential relationship between two ideas when
the inference is indicated with conclusion indicator like “therefore.” Before taking a critical
thinking class, 66.59% of students are confidently able to correctly identify the inferential
relationship between two ideas when the inference is indicated with reason indicator like
“because.” After taking a critical thinking class, 82.8% of students are confidently able to
correctly identify the inferential relationship between two ideas when the inference is indicated
with reason indicator like “because.”
Before taking a critical thinking class, 43.17% of students are confidently able to
recognize two ideas as dependent reasons. After taking a critical thinking class, 71.7% of
students are confidently able to recognize two ideas as dependent reasons.
Before taking a critical thinking class, 53.58% of students are confidently able to
distinguish between independent lines of reasoning. After taking a critical thinking class, 67% of
students are confidently able to distinguish between independent lines of reasoning.
Slide 13 The importance of all this, of course, is not the diagram itself but the process that’s
used to generate the diagram. I tell my students that even if they never diagram another
argument after they leave the class, they will always understand an argument by distinguishing
between the important ideas and unimportant ideas and identifying how the important ideas
work together to support the ultimate conclusion.
Slide 14 Once an argument is analyzed, we can evaluate it with more confidence. A premise is
good only if it’s true and can be believed by someone who doesn’t already believe the ultimate
conclusion. An inference is good just in case if the ideas at the top of the inference were true
then the idea at the bottom of the inference would be true. An argument is good only if it has at
least one good line of reasoning. And good arguments establish the probable truth of their
ultimate conclusions; bad arguments tell us nothing about their ultimate conclusions.
Critical Thinking 4
Dona Warren
Pre-Post test results indicate that before taking a critical thinking class, 78.74% of
students are confidently able to reject a false premise. After taking a critical thinking class, 86%
of students are confidently able to reject a false premise.
Before taking a critical thinking class, 9.978% of students are confidently able to reject a
premise that assumes the conclusion. After taking a critical thinking class, 9.95% of students are
confidently able to reject a premise that assumes the conclusion.
Before taking a critical thinking class, 19.52% of students are confidently able to reject a
particular kind of faulty inference (an inference that commits the fallacy of negating the
antecedent). After taking a critical thinking class, 57.2% of students are confidently able to
reject this inference.
Before taking a critical thinking class, 39.91% of students confidently recognize that a
bad argument tells us nothing about the ultimate conclusion. After taking a critical thinking
class, 69.7% of students confidently recognize that a bad argument tells us nothing about the
ultimate conclusion.
Slide 15 Of course, it’s naïve to assume that we can generate a complete evaluation for all of the
arguments that confront us. I tell my students that it’s important to go as far along the
evaluation path as they can, without being bullied into going any further than that.
Evaluation usually starts with a general feeling of dissatisfaction with an argument. I’ve
found that some students react to this dissatisfaction by blaming themselves while other
students react to this dissatisfaction by blaming the author of the argument. I try to help my
students to avoid immediately falling into either habit. All they should conclude at this point is
that there’s a problem somewhere, either in their understanding of the argument or in the
argument themselves. Further thought may lead them to decide that the argument is right after
all, or it might deepen their conviction that the problem lies within the argument. If they decide
that there’s a problem with the argument, they might only be able to identify the general area
where things go wrong, without being able to pinpoint the precise source of the trouble. If they
think about it some more, they might be able to determine which particular premises or
inferences are going awry.
Slide 16 Should they be able to pinpoint particularly problematic premises or inferences, they
will want to be able to articulate why these premises or inferences fail. I’ve found that many
students can’t get much further than “This part’s bad,” so I present them with some fairly
formulaic responses until they gain more fluency.
Slide 17 So much for the general contours of recognizing, analyzing, and evaluating arguments.
Constructing arguments can be a bit more tricky to teach because it requires greater creativity. I
encourage my students to always start by having a question firmly in mind, for instance “Should
we try to teach critical thinking skills in general education courses?” This question can then
direct their research, and their research can guide them to an answer. Let’s take the answer to
our question to be “Yes. We should try to teach critical thinking skills in general education
courses.” This answer to our question becomes the ultimate conclusion of our argument, and
Critical Thinking 5
Dona Warren
we construct an initial argument by identifying some reasons to think that our conclusion is true
and diagramming the resulting chain of reasoning.
Slide 18 We might, for instance, decide that we should teach critical thinking in general
education courses because critical thinking will guarantee true beliefs, which means that critical
thinking is important, coupled with the claim that many students don’t already possess these
important skills.
At this point, we need to critically examine our reasoning and a clear problem here is the
premise that critical thinking will guarantee true beliefs. That’s just not the case, so let’s change
it.
Slide 19 Instead of saying that critical thinking will guarantee true beliefs, we can make the
more modest and plausible claim that it will help us to avoid being taken in.
Now we might see that even if critical thinking skills are important and even if many
students don’t have strong critical thinking skills already, it doesn’t follow that we should try to
teach these skills unless students can learn these skills and it’s our responsibility to teach
important, learnable skills. Let’s add those ideas to strengthen that inference.
Slide 20 At this point, we might imagine that someone could challenge the assumption that
students don’t already have critical thinking skills. Someone else might challenge the
assumption that students can learn these skills if they don’t already have them.
Slide 21 We can support both of these claims by citing the pre and post test data that we’ve
already seen.
Slide 22 I think that this argument is pretty good and that it successfully establishes the
importance of teaching critical thinking skills in general education courses.
Slide 23 This means that we can write up the argument in a passage.
Slide 24 I hope that this presentation has made critical thinking a little bit clearer and pointed
out some of the skills that fall under the concept. You probably already know what critical
thinking skills are especially important for your students. I’d recommend focusing on no more
than three such skills at first because I think it’s more important for students to master a few
skills than to gain a passing acquaintance with many. And I’d recommend setting the bar lower
than you think necessary because it’s very easy to over-estimate the critical thinking skills that
our students bring to class. The most important thing, however, is just to do it. Devote some
attention to critical thinking skills. You’ll be helping to make the world a better place.