CS 146 The Big Picture in Computer Science

1. CS 146The Big Picture in Computer Science Prof. Daniel Ernst February 28th, 2011 Computational and Critical Thinking Critical Thinking slides mostly created by Dr. Michael Wick

2. Main Message “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

3. Computational Thinking 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

4. Computational Thinking – for whom? • 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

5. Computational Thinking – about what? About people, not computers Trying 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?)

6. Computational Thinking – involves what? • At a high level • Problem solving • Designing models, systems and solutions • Critical thinking about computational issues • More later about Critical Thinking • 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

7. Computational Thinking – involves what? • 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

8. Computational Thinking – involves what? (2) • 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. Codeissue – 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

9. Computational Thinking – involves what? (3) • 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

10. Computational Thinking – involves what? (4) • 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

11. Computational Thinking - Summary • 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

12. 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.

13. Reasoning CRITICAL THINKING SKILLS Analyzing Evaluating Decision Making Problem Solving What is Critical Thinking?

14. The most significant critical (intellectual) thinking standards: Clarity Accuracy Precision Relevance Depth Breadth Logic Fairness Universal Intellectual Standards

15. 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? Clarity is the gateway standard Source: http://www.fctl.ucf.edu/tresources/content/Ruland-CriticalThinkingStandards.pdf

16. 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.

17. Accuracy Is that really true? How could we check that? How could we find out if that is true? This chicken weighs over 300 pounds. A statement can be clear but not accurate Source: http://www.fctl.ucf.edu/tresources/content/Ruland-CriticalThinkingStandards.pdf

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

19. Could you give more details? Could you be more specific? Precision Yao Ming is TALL! A statement can be both clear and accurate, but not precise Source: http://www.fctl.ucf.edu/tresources/content/Ruland-CriticalThinkingStandards.pdf

20. 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.

21. How is that connected to the question? How does that bear on the issue? Relevance 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. Source: http://www.fctl.ucf.edu/tresources/content/Ruland-CriticalThinkingStandards.pdf

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

23. 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 A statement can be clear, accurate, precise, and relevant, but superficial. Source: http://www.fctl.ucf.edu/tresources/content/Ruland-CriticalThinkingStandards.pdf

24. 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?

25. 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...? Breadth Headache!!! A line of reasoning may be clear, accurate, precise, relevant, and deep, but lack breadth. Source: http://www.fctl.ucf.edu/tresources/content/Ruland-CriticalThinkingStandards.pdf

26. 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.

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

28. 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?

29. Critical thinking demands that our thinking be fair. Open-minded Impartial Free of distorting biases and preconceptions Fairness Fair-mindedness is an essential attribute of a Critical Thinker. Source: http://www.fctl.ucf.edu/tresources/content/Ruland-CriticalThinkingStandards.pdf

30. 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.

31. The most significant critical (intellectual) thinking standards: Clarity Accuracy Precision Relevance Depth Breadth Logic Fairness Universal Intellectual Standards

32. 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.

33. 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.

34. 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.

35. 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?

36. 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.”

37. 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.

38. Five Powerful Barriers to Critical Thinking: Barriers to Critical Thinking Egocentrism Sociocentrism Unwarranted Assumptions Wishful Thinking Relativistic Thinking

39. 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: • Self-interested thinking • Group bias • Self-serving bias • Conformism

40. Which critical thinking barrierdoes Ali display in this passage? A) Self-interested thinking B) Group bias C) Self-serving bias D) Conformism Quiz – Question 2 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."

41. Which critical thinking barrierdoes Lee exhibit? A) Self-interested thinking B) Stereotyping C) Group bias D) Conformism Quiz – Question 3 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.

42. Which critical thinking barrierdoes Suzie exhibit? A) Stereotyping B) Self-interested thinking C) Wishful thinking D) Relativistic thinking Quiz – Question 4 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.

44. Questioning • Questioning is one approach to motivate others to: • Get information • Test understanding • Develop interest • Evaluate the ability of individuals towards understanding certain things. “A person who asks questions is a person who thinks.”’ - William Wilen

45. 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. 5Ws H What Who Where When Why How

46. Questioning - Bloom’s Taxonomy Synthesize Why? How? Higher-Level Thinking Evaluate Analyze Apply Understand What? Who? When? Where? Lower-level Thinking Remember

47. 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 canthink out of the box.” – Pak Lah

48. 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? Questioning – Apply

49. 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… Questioning – Analyze

50. 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… Questioning – Evaluate