Cri  Թ tical Thinking

1. Critical Thinking – jump to 14 for slides in English CriԹtical Thinking Luís Moniz Pereira Departamento de Informática FCT/UNL 1st sem. 06/07

2. Enquadramento • Disciplina da área de “soft skills”. Tem uma relevância geral para qualquer área científica, em particular para a Informática, pela forte ligação com a lógica para análise de argumentos, hipóteses, e especificações de problemas ou soluções.

3. Objectivos – “Saber” • Interpretar correctamente experiências ou dados experimentais. • Inferir conclusões a partir de informações dadas, e ajuizar da credibilidade das fontes. • Identificar erros de inferência ou contradições e resolvê-las (debugging). • Saber argumentar e identificar compromissos, bem como lidar com ambiguidades e avaliar opções. • Perceber explicações lógicas e de causalidade.

4. Objectivos – “Fazer” • Elaborar argumentos válidos e gerir hipóteses e contextos. • Comunicar ideias e sua sustentação lógica. • Descrever correctamente experiências, resultados, e conclusões. • Preferir hipóteses explicativas e testá-las. • Dar e interpretar explicações causais e lidar com suas alternativas.

5. Objectivos – “Soft Skills” • Comunicação e debate. Precisão de linguagem. • Pensamento crítico. Procura de fontes de informação. • Raciocínio disciplinado. • Avaliação objectiva de argumentos e factos. • Capacidade de decidir usando trade-offs sobre valores de utilidade.

6. Esforço do aluno - ECTS

7. Funcionamento - Docentes • Docentes • Teóricas: 3as 17–19 anfiteatro 1.27 II Prof. Cat. Luís Moniz Pereira lmp@di.fct.unl.pt http://centria.di.fct.unl.pt/~lmp/ gab. 2.47 Ed II, ext. 10717 atendimento: 3as 12-13 • Práticas (3 turnos): 6as9–11, 11–13, 14-16 sala 3.5 Ed. VII Prof. Aux. Ludwig Krippahl ludi@di.fct.unl.pt http://centria.di.fct.unl.pt/~ludi/ gab. 2.41 Ed II, ext. 10765 atendimento: 6as 13-14

8. Funcionamento – Página PC • Sítio http://ssdi.di.fct.unl.pt/lei/pc/ com: • Objectivos, programa, avaliação, etc • Sumários das teóricas e das práticas • Slides e gravação digital de som de cada aula • Documentação, exercícios, resultados da avaliação • Links externos • Software • Lista de distribuição de mail, subscrevam ! https://mail.di.fct.unl.pt/mailman/listinfo/lei-pc • Mail para envio de trabalhos: practicaspc@di.fct.unl.pt

9. Funcionamento – Avaliação 1 • Componente prática com 4 fichas individuais, de cerca de 100 palavras, aproximadamente cada 2-3 aulas. Estima-se em 4 horas o esforço para cada ficha. • Dois trabalhos individuais, de cerca de 500 palavras cada. Estima-se em 15 horas o esforço para cada trabalho. • Participação e desempenho nas discussões das aulas práticas. • Estas componentes valem 40% da nota final.

10. Funcionamento – Avaliação 2 • Exame final escrito de 2 horas: • Com algo como 4 perguntas das quais se podem escolher 2, com respostas de desenvolvimento. • As respostas não são necessariamente longas (e.g. 3-4 páginas), mas terão material para consultar (algumas páginas), e que criar um argumento estruturado, o que poderá exigir alguns rascunhos. • Esta componente vale 60% da nota final. • Obrigatoriedade de presença em 9T e em 9P.

11. Programa - 1 • Estrutura de argumentos • Estrutura lógica formal. • Requisitos de validade. Ambiguidade. • Erros em argumentos falaciosos • Erros de raciocínio. Remoção de contradições. • Mau uso da evidência. • Erros linguísticos e recurso a considerações pessoais.

12. Programa - 2 • Avaliação crítica • Avaliação de experiências pessoais. • Crença e conhecimento. • Afirmações e o ónus da prova. • Comunicação e fontes de informação • Decisão e "trade-offs" • Avaliação de opções. • Enviezamentos. Equilíbrios.

13. Programa - 3 • Raciocínio Científico • Importância da testabilidade de hipóteses. • Preferências explicativas. • Modelos teóricos e sua avaliação. • Epistemologia. • Hipóteses causais e estatísticas. • Reproductibilidade, confirmação independente, e arbitragem.

14. Main Bibliography • Alec Fisher, 2001, Critical Thinking - an introduction, Cambridge U.P. • Jonathan Baron, 2000, Thinking and Deciding, Cambridge U.P., 3rd ed. • Ronald Griere, 1997, Understanding Scientific Reasoning, Harcourt Brace, 4th ed. • Douglas Walton, 2004, Abductive Reasoning, The University of Alabama Press. • M. Neil Browne, Stuart M. Keeley, 2004, Asking the Right Questions, Pearson Prentice Hall, 7th ed.

15. Two sides of the coin • Critical thinking has two sides to it: - That of the consumer of information. - That of the producer. • Often, the stress is put just on the general public, viewed as the critical consumer. • Here, we shall stress the critical producer side too: university students are trained to be producers of knowledge, activities, decisions and designs, and hence should strive to be self-critical producers.

16. Definitions – JohnDewey • Critical thinking is the active, persistent, and careful consideration of a belief or supposed form of knowledge, in the light of the grounds which support it, and the further conclusions to which it tends.

17. Definitions – Edward Glaser on Dewey • Critical thinking is: - An attitude of being disposed to consider, in a thoughtful way, the problems and and subjects that come within the range of one’s experience. - Knowledge of the methods of logical inquiry and reasoning, and some skill in applying those methods. • It calls for a persistent effort to examine any belief or supposed form of knowledge in the light of the evidence that supports it and the further conclusions to which it tends.

18. Definitions – RobertEnnis • Critical thinking is reasonable, reflective thinking that is focussed on deciding what to believe or do.

19. Definitions – Richard Paul • Critical thinking is that mode of thinking – about any subject, content or problem – in which the thinker improves the quality of his thinking, by skilfully taking charge of the structures inherent in thinking and imposing intellectual standards upon them.

20. Definitions – Michael Scriven • Critical thinking is skilled and active interpretation and evaluation of observations and communications, information and argumentation.

21. Definitions – Wikipedia 1 • Critical thinking consists of a mental process of analyzing or evaluating information, particularly statements or propositions that people have offered as true. • It forms a process of reflecting upon the meaning of statements, examining the offered evidence and reasoning, and forming judgments about the facts.

22. Definitions – Wikipedia 2 • Critical thinkers can gather such information from observation, experience, reasoning, and/or communication. • Critical thinking has its basis in intellectual values that go beyond subject-matter divisions and which include: clarity, accuracy, precision, evidence, thoroughness and fairness.

23. Definitions – Wikipedia 3 • The process of critical thinking involves acquiring information and evaluating it to reach a well-justified conclusion or answer. • Part of critical thinking comprises informal logic. • Given research in cognitive psychology, educators increasingly believe that schools should focus more on teaching their students critical thinking skills than on memorizing facts by rote-learning.

24. Definitions – William G. Sumner 1 • Critical thinking is the examination and test of propositions of any kind which are offered for acceptance, in order to find out whether they correspond to reality or not. • The critical faculty is a product of education and training. It is a mental habit and power.

25. Definitions – William G. Sumner 2 • Critical thinking is such a prime condition of human welfare that men and women should be trained in it. • Critical thinking is our only guarantee against delusion, deception, superstition, and misapprehension of ourselves and our earthly circumstances.

26. Bootstrap Thinking critically about critical thinking ! Critical thinking is critical !

27. Argumentation - 1 • We often encounter situations in which someone is trying to persuade us of a point of view by presenting reasons for it. • This is called “arguing a case” or “presenting an argument”.

28. Argumentation - 2 • Sometimes it is easy to to see what the issues and conclusions are, and the reasons presented, but sometimes not. • Before we evaluate and argue a point of view we must identify its issues, conclusions, and reasons. • And then clearly present our own.

29. Asking the right questions - 1 • What are the issues and the conclusions? • What are the reasons? • Which words or phrases are ambiguous? • What are the value conflicts and assumptions? • What are the descriptive assumptions? • Are there any fallacies in the reasoning?

30. Asking the right questions - 2 • How good is the evidence? • Are there rival causes? • Are the statistics deceptive? • What significant information is omitted? • What reasonable conclusions are possible? • Are the best practice precepts followed?

31. What are the issues and conclusions? - 1 • Before we can evaluate an author’s argument, we must clearly identify the issues and conclusions. • How can we evaluate an argument if we don’t know exactly what the author is trying to persuade us to believe? • Finding an author’s main points is the first step in deciding whether we will accept or reject it.

32. What are the issues and conclusions? - 2 • An issue is a question or controversy responsible for the conversation or discussion. It is the stimulus for what is being said. • Descriptive issues are those that raise questions about the accuracy of descriptions of the past, present, or future. • Prescriptive issues are those that raise questions about what we should do, or what is right or wrong, good or bad. • A conclusion is the message that the speaker or writer wishes you to accept.

33. What are the issues and conclusions? - 3 • Clues for finding them: • Ask what the issue is: look at title and opening paragraphs; skim through. • Look for indicator words: the truth is, hence, ... • Look in likely locations: beginning, end, summary. • Remember what a conclusion is not: examples, ... • Check the author’s context: background, organizations, bias, ... • Ask the question “and therefore?”

34. What are the reasons? - 1 • Once we have identified an issue and conclusion, we need to understand why an author has come to that conclusion. Reasons are the why. • If the author provides good reasons, we might be persuaded to accept the conclusion. First, we are simply concerned with identifying the reasons. Next, we decide whether to accept or reject it.

35. What are the reasons? - 2 • Inferential reasons are explanations offered as a basis for why we should believe a particular conclusion. • They rely on facts, evidence, assumptions, and inferences. • They have an intent. • Their quality varies. • Argument = Conclusion + Reasons • We distinguish them from causal reasons.

36. What are the reasons? - 3 • Clues for finding them: • Circle indicator words. • Underline reasons and conclusions in different colour, and label them. • After reading long passages, make a list of the reasons and conclusions in them. • Use a diagram structure with arrows and labels to designate relationships between reasons and conclusions.

37. Value conflicts and assumptions - 1 • While an author usually offers explicit reasons why he comes to a certain conclusion, he also makes (implicit) assumptions leading to it, on the basis of his values. • By identifying value conflicts, we determine whether the author’s value preferences match our own, and can then dispute them.

38. Value conflicts and assumptions - 2 • Value assumptions usually are: • Hidden or unstated (in most cases). • Taken for granted. • Influential in determining the conclusion. • Potentially deceptive.

39. Value conflicts and assumptions - 3 • Clues for finding them: • Investigate the author’s background. • Ask “Why do the consequences of the author’s position seem so important to him?” • Search for similar social controversies, in order to find analogue value assumptions. • Use reverse role-playing, by taking his position. • Look for usual value conflicts.

40. What are the descriptive assumptions? - 1 • When we identify descriptive assumptions, we find the link between a reason and the author’s conclusion, and it may be flawed. • We want to accept a conclusion only if there are good reasons that lead to the conclusion on the basis of the descriptive assumptions.

41. What are the descriptive assumptions? - 2 • Clues to finding them: • Keep thinking about the gap between conclusion and reasons. • Look for ideas that support reasons. • Identify with the opposition. • Recognize the potential existence of other means for attaining the advantages referred in the reasons. • Learn more about the issues.

42. The Socratic method - 1 • What do you mean by _____________ ? • How did you come to that conclusion? • Why do you believe that you are right? • What is the source of your information? • What assumption has led you to that conclusion? (see Wikipedia)

43. The Socratic method - 2 • What happens if you are wrong? • Can you give me two sources who disagree with you and explain why? • Why is this significant? Does it matter? • How do I know you are telling me the truth? • What is an alternate explanation for this phenomenon?

44. Best Practice Precepts [... next] • Arguments • Possibility of the Impossible • Belief, Truth, and Reality • Knowledge, Belief, and Evidence • Scientific Thinking • Bias

45. Arguments - 1 • Itemize opinions from all relevant sides of an issue and collect logical arguments supporting each. • Break the arguments into their constituent statements and draw out various additional implications from these statements. • Examine these statements and implications for internal contradictions.

46. Arguments - 2 • Locate opposing claims between the various arguments and assign relative weightings to opposing claims: • Increase the weighting when the claims have strong support, especially distinct chains of reasoning or different news sources, decrease the weighting when the claims have contradictions. • ...

47. Arguments - 3 • Adjust weighting depending on relevance of information to central issue. • Require sufficient support to justify any incredible claims. • Otherwise, ignore these claims when forming a judgment. • Assess the weights of the various claims.

48. Arguments - 4 • Once we have identified an argument, we identify keywords or phrases within its reasoning, that might have alternative well-defined meanings. • We determine whether or not the author explicitly uses one of those definitions. If not, and one of them changes our acceptance of the conclusion, then an ambiguity has been identified. • This is an important step in accepting or not some conclusion.

49. Possibility of the Impossible - 1 • Just because something is logically possible doesn’t mean that it’s real. • Just because a claim hasn’t been conclusively refuted doesn’t mean that it’s true. • Just because a claim hasn’t been conclusively proven doesn’t mean that it’s false.

50. Possibility of the Impossible - 2 • Just because something seems physically impossible doesn’t mean that it is. • Just because something is physically possible doesn’t mean that it’s real. • One can’t believe impossible things. • We have to live today by what truth we can get today, and be ready tomorrow to call it falsehood.