PROF. DANIEL ERNSTFEBRUARY 28 T H , 2011

COMPUTATIONAL AND CRITICAL THINKING

CS 146The Big Picture in Computer Science

Critical Thinking slides mostly created by Dr. Michael Wick

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“Thinking like a computer scientist means more than being able to program a computer. It requires thinking at multiple levels of abstraction.”

- Dr. Jeannette Wing

Main Message

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A relatively new idea

First put forth by Dr. Jeannette Wing, Carnegie Mellon University (CMU) in 2006

Developed since then through presentations, workshops and other communication

Computational Thinking

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Not just computer scientists!Dr. Wing sees this as important for

children as well as university students everyone as well as computer scientists

Implication: we have to think about what CS material we teach K-12 as well as what is taught at the university level

Computational Thinking – for whom?

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About people, not computersTrying to package what we, as humans, do

based on what we’ve learned from 50+ years of computer science work

Supplements other analytical forms of thinking (mathematical, engineering, scientific?)

Computational Thinking – about what?

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At a high level1. Problem solving2. Designing models, systems and solutions3. Critical thinking about computational issues

More later about Critical Thinking

4. Understanding human behavior in regard to computing

Another place where general education matters!

Note that programming is part of this, but is certainly not the whole package

Computational Thinking – involves what?

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At a detailed level◦ Abstraction – different levels of organization of

concepts Example: data type and instance variable

◦ Algorithms – Decomposing a problem into sequential (and parallel) steps E.g. sequence for a basic web request through the HTTP

protocol◦ Modeling – related to abstraction, the ability to build

a representative model for a system or situation E.g. a program to simulate the Davies Center food court

Computational Thinking – involves what?

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More detailed level items:◦ Recursion – a process can be defined in terms of or

“call” (programmatically) itself Example: factorial can be defined in terms of itself

(how?)◦ Data vs. Code issue – recognizing the blurred line

(and advantages and disadvantages) between represented information and represented processing E.g. One byte can be a character, integer, part of a

floating point number, or part of an instruction◦ Planning, Searching, Scheduling, Learning,

Dealing with Uncertainty E.g. Autonomous vehicle programming

Computational Thinking – involves what? (2)

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More detailed level items:◦ Evaluating and Accomplishing Efficiency

E.g. Linear vs. Exponential time algorithms◦ Prevention/Detection/Recovery from worst-case

scenarios E.g. Computer security

◦ Parallel Processing – activities that don’t rely on each other can be accomplished concurrently E.g. checking values in an array to find some value

◦ Planning For Failure – building fault tolerance into systems E.g. use of exception handling in Java, C++ to catch

incorrectly formatted input

Computational Thinking – involves what? (3)

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More detailed level items:◦ Heuristic Reasoning – developing approximation

functions to represent best guess and move toward solution E.g. evaluating the quality of a position in tic-tac-toe by

counting pieces plus adding value for owning certain positions (e.g. center)

◦ Redefining Problems – e.g. re-structuring problems by use of “reduction, embedding, transformation, or simulation” (or emulation) E.g. modeling new hardware chips by building a software

emulator of that chip before actually manufacturing it

Computational Thinking – involves what? (4)

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Computational thinking is more about: Developing conceptual skill

than just programming Judgment and analysis

than rote application of rules Developing ideas and concepts for problem solving

than focusing on the artifacts that those processes create Building “virtual” systems

than just physical ones – though physical systems are a part of an overall computational system

Computational Thinking - Summary

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What is Critical Thinking?

Critical Thinking is the general term given to a wide range of cognitive and intellectual skills needed to:

Effectively identify, analyze, and evaluate arguments. Discover and overcome personal prejudices and

biases. Formulate and present convincing and relevant

reasons in support of conclusions. Make reasonable, intelligent decisions about what to

believe and what to do.

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What is Critical Thinking?

CRITICAL THINKING

SKILLS

Analyzing

Reasoning

Evaluating

Decision Making Problem Solving

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The most significant critical (intellectual) thinking standards:

Clarity Accuracy Precision Relevance Depth Breadth Logic Fairness

Universal Intellectual Standards

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Clarity

Could you elaborate further on that point?Could you express that point in another way?Could you give me an illustration?Could you give me an example?

Source: http://www.fctl.ucf.edu/tresources/content/Ruland-CriticalThinkingStandards.pdf

Clarity is the gateway standard Clarity is the gateway standard

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Clarity

Give several examples of places in the areas of computer science that we’ve discussed or that you know about where clarity could be an issue.

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Accuracy

Is that really true?How could we check that?How could we find out if that is true?

Source: http://www.fctl.ucf.edu/tresources/content/Ruland-CriticalThinkingStandards.pdf

This chicken weighs over 300

pounds.

A statement can be clear but not accurateA statement can be clear but not accurate

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Accuracy

Think of a statement you heard recently that was clear but inaccurate.

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Precision

Could you give more details?Could you be more specific?

Source: http://www.fctl.ucf.edu/tresources/content/Ruland-CriticalThinkingStandards.pdf

A statement can be both clear and accurate, but not precise

A statement can be both clear and accurate, but not precise

Yao Ming is TALL!

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Precision

Identify a situation in which the details and specifics were important. Then identify the negative consequences that resulted because you didn’t get the details you needed to think well in the situation.

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Relevance

How is that connected to the question?

How does that bear on the issue?

Source: http://www.fctl.ucf.edu/tresources/content/Ruland-CriticalThinkingStandards.pdf

I studied hard all semester, therefore I

should get A+.

A statement can be clear, accurate, and precise, but not relevant to the question at issue.

A statement can be clear, accurate, and precise, but not relevant to the question at issue.

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Relevance

Can you identify circumstances in which people tend to introduce irrelevant considerations into a discussion?

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How does your answer address the complexities in the question?

How are you taking into account the problems in the question?

Is that dealing with the most significant factors?

Depth

Source: http://www.fctl.ucf.edu/tresources/content/Ruland-CriticalThinkingStandards.pdf

A statement can be clear, accurate, precise, and relevant, but superficial.A statement can be clear, accurate,

precise, and relevant, but superficial.

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Depth

Identify a problem you have experienced lately where the solution presented to the problem was superficial in nature.

If decisions were based on this surface thinking, what were the consequences that followed from the decision?

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Breadth

Do we need to consider another point of view?

Is there another way to look at this question?

What would this look like from another view?

What would this look like from the point of view of...?

Source: http://www.fctl.ucf.edu/tresources/content/Ruland-CriticalThinkingStandards.pdf

A line of reasoning may be clear, accurate, precise, relevant, and deep, but lack breadth.A line of reasoning may be clear, accurate,

precise, relevant, and deep, but lack breadth.

Headache!!!

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Breadth

Consider the question, “Is abortion morally justified?” Some argue yes, others argue no.

Try to state and elaborate on each of these points of view in detail. Try to present each point of view in such a way that a person who actually takes that position would assess it as accurate.

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Logic

Does this really make sense?Does that follow from what you said?How does that follow?But before you implied X and now you are

saying “not X”; how can both be true?Need to know the rules of logic.

Source: http://www.fctl.ucf.edu/tresources/content/Ruland-CriticalThinkingStandards.pdf

All professors are human.I am a human.Therefore, I am a professor.

When the combination of thoughts are mutually supporting and make sense in combination,

the thinking is "logical.“

When the combination of thoughts are mutually supporting and make sense in combination,

the thinking is "logical.“

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Logic

Remember a time when decisions at work or home seemed to be based on illogical thinking.

What was the thinking in the situation that you consider to be illogical?

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Fairness

Critical thinking demands that our thinking be fair.

Open-minded ImpartialFree of distorting biases and preconceptions

Source: http://www.fctl.ucf.edu/tresources/content/Ruland-CriticalThinkingStandards.pdf

Fair-mindedness is an essential attribute of a Critical Thinker.

Fair-mindedness is an essential attribute of a Critical Thinker.

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Fairness

Think of a situation in the last several weeks where you were not fair. Try to look for situations where your behavior was selfish or self-serving and as a result, you negated another person’s desires or rights.

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The most significant critical (intellectual) thinking standards:

Clarity Accuracy Precision Relevance Depth Breadth Logic Fairness

Universal Intellectual Standards

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Practice

Identify the Universal Intellectual Standards not followed in this statement.

Since we have never been visited by extraterrestrials, and have had no communication from outer space, we can safely assume that intelligent life exists only on our own planet.

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Practice

Identify the Universal Intellectual Standards not followed in this statement.

It is pretty obvious that smoking marijuana causes people to crave more potent drugs, like cocaine and heroin. Statistics show that almost all the people who become addicted to drugs smoked marijuana before they began using more potent drugs.

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Practice

Identify the Universal Intellectual Standards not followed in this statement.

The increase in violence by adolescent gangs in this country is just another result of the liberal thinking that has more sympathy for criminals than for their victims.

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Practice

Identify the Universal Intellectual Standards not followed in this statement.

Why are the people in this class so much better looking and intelligent than people in other introductory classes?

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Practice

Identify the Universal Intellectual Standards not followed in this statement.

A mother was trying to dissuade her son from marrying a girl he had met just three weeks before. The son’s response was “But I know she’s the one; the first time I saw her I began to tremble and see spots before my eyes, and I had flutters in my chest and strange sensations in my stomach. When I’m with her, I feel like I could just take off and fly.”

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Practice

Identify the Universal Intellectual Standards not followed in this statement.

I looked at several issues of the Journal of Parapsychology, a periodical that publishes research on psychic phenomena. Every article confirmed the existence of ESP, so I don’t understand why most psychologists are skeptical about it.

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Five Powerful Barriers to Critical Thinking:

Barriers to Critical Thinking

Self-centered thinking self-interested thinking self-serving bias

Group-centered thinking Group bias Conformism

Beliefs that are presumed to be true without adequate evidence or justification

Assumption Stereotyping

Believing that something is true because one wishes it were true.

The truth is “just a matter of opinion” Relativism

Subjectivism Cultural relativism

Egocentrism

Unwarranted Assumptions

Sociocentrism

Relativistic Thinking

Wishful Thinking

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Quiz – Question 1

In a 1989 international study of 13-year-olds, Koreans finished first in mathematics and Americans finished last. Yet when asked whether they thought they were "good at mathematics," only 23 percent of Koreans said "yes," compared to 68 percent of Americans. Which critical thinking barrier do the American students

exhibit:

A) Self-interested thinking B) Group biasC) Self-serving biasD) Conformism

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Quiz – Question 2

Which critical thinking barrier does Ali display in this passage?

A) Self-interested thinking B) Group biasC) Self-serving biasD) Conformism

Muhammad Ali [speaking in Zaire, Africa]: "There's no country as great as the smallest city in America. I mean [here in Zaire] you can't watch television. The water won't even run right. The toilets won't flush. The roads, the cars- there's nothing as great as America."

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Quiz – Question 3

Which critical thinking barrier does Lee exhibit?

A) Self-interested thinking B) StereotypingC) Group biasD) Conformism

Adam: My friend Andy is a 1st year student at UWEC. He is cool, loves hanging out, and has a very laid-back

personality.

Lee: I bet he’s from Minnesota.

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Quiz – Question 4

Which critical thinking barrier does Suzie exhibit?

A) StereotypingB) Self-interested thinkingC) Wishful thinkingD) Relativistic thinking

Suzie: I can't believe I got a B- on this marketing paper. My friend Sarah turned in this same paper in a different marketing class last semester, and she got an A.

Ali : Don't you realize it's wrong to plagiarize someone else's work?

Suzie: That's your opinion. What's wrong for one person isn't necessarily wrong for another, and I say there's nothing wrong with plagiarism- as long as you don't get caught.

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Questioning

Questioning is one approach to motivate others to:

Get informationTest understandingDevelop interestEvaluate the ability of individuals towards

understanding certain things.“A person who asks questions

is a person who thinks.”’- William Wilen

“A person who asks questions is a person who thinks.”’

- William Wilen

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Questioning - Five Ws and H

The Five W’s and H, is an influential, inspirational and imaginative checklist (often used by journalists) to generate:

Data-gathering questions, during the early stages of problem solving when you are gathering data.

Idea-provoking questions (e.g. whilst brainstorming).

Criteria for evaluating options.

WhatWhoWhereWhenWhy

How

5Ws

H

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Questioning - Bloom’s Taxonomy

Remember

Understand

Apply

Analyze

Synthesize

Evaluate

Lower-level Thinking

Higher-Level Thinking

Why?How?

What?Who?When?Where?

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Questioning – Understand

Understand – Seek to select and organize facts and ideas, discovering the relationships between them.

What is the main idea of…Retell in your on words what happened.

“There are many students who are educated

but few who can think out of the box.” – Pak Lah“There are many students who are educated

but few who can think out of the box.” – Pak Lah

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Questioning – Apply

Apply – Help us take knowledge or concepts learnt in one situation and apply them to other situations.

How would you apply the principles of decision making when seeking a job?

How do you apply this rule in your daily life?

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Questioning – Analyze

Analyze - To separate the entire process into component parts and understand the relation of these parts to the whole.

What are the parts or features of …What evidence can you present to support…

Explain the reasons why you think…

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Questioning – Evaluate

Evaluate - to make informed judgments and decisions by determining the reliability of things.

Do you agree with…? Why or why not? What criteria would you use to

assess…

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Questioning – Synthesize

Synthesize - to combine ideas and come to a conclusion.

What ideas can you add to…What might happen if you combine … with …?What solution would you suggest for…

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Questioning – Create

Create - to build on other ideas and develop something new and useful.

How and where is what’s been done so far not sufficient to (completely) solve the problem?

What might happen if you combine … with …?What new idea can solve the problem?

NOTE: this is the core of much research!

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Asking the Right Questions

http://www.pbs.org/wgbh/nova/tech/profile-von-ahn.html