Presentation is loading. Please wait.

Presentation is loading. Please wait.

1 Thinking Critically with Psychological Science Chapter 1.

Similar presentations

Presentation on theme: "1 Thinking Critically with Psychological Science Chapter 1."— Presentation transcript:

1 1 Thinking Critically with Psychological Science Chapter 1

2 2 Thinking Critically with Psychological Science The Need for Psychological Science The limits of Intuition and Common Sense The Scientific Attitude The Scientific Method

3 3 Thinking Critically … Description The Case Study The Survey Naturalistic Observation

4 4 Thinking Critically … Correlation Correlation and Causation Illusory Correlation Perceiving Order in Random Events

5 5 Thinking Critically … Experimentation Exploring Cause and Effect Evaluating Therapies Independent and Dependent Variables

6 6 Thinking Critically … Statistical Reasoning Describing Data Making Inferences FAQs About Psychology

7 7 Impression of Psychology With hopes of satisfying curiosity, many people listen to talk-radio counselors and psychics to learn about others and themselves. Dr. Crane (radio-shrink) Psychic (Ball gazing)

8 8 The Need for Psychological Science Intuition & Common Sense Many people believe that intuition and common sense are enough to bring forth answers regarding human nature. Intuition and common sense may aid queries, but they are not free of error.

9 9 Limits of Intuition Personal interviewers may rely too much on their gut feelings when meeting with job applicants. Taxi/ Getty Images

10 10 Errors of Common Sense Try this ! Pennies in a cup

11 11 Hindsight Bias is the I-knew-it-all-along phenomenon. After learning the outcome of an event, many people believe they could have predicted that very outcome. We only knew the stocks would plummet after they actually did plummet. Hindsight Bias

12 12 Overconfidence Sometimes we think we know more than we actually know. Anagram BARGEGRABE ENTRYETYRN WATERWREAT How long do you think it would take to unscramble these anagrams? People said it would take about 10 seconds, yet on average they took about 3 minutes (Goranson, 1978).

13 13 Psychological Science 1.How can we differentiate between uniformed opinions and examined conclusions? 2.The science of psychology helps make these examined conclusions, which leads to our understanding of how people feel, think, and act as they do!


15 15 The Scientific Attitude The scientific attitude is composed of curiosity (passion for exploration), skepticism (doubting and questioning) and humility (ability to accept responsibility when wrong).

16 16 Critical Thinking Critical thinking does not accept arguments and conclusions blindly. It examines assumptions, discerns hidden values, evaluates evidence and assesses conclusions. The Amazing Randi Courtesy of the James Randi Education Foundation

17 17 Scientific Method Psychologists, like all scientists, use the scientific method to construct theories that organize, summarize and simplify observations.

18 18 Psychologists Analyze Data Scientifically Behavior must be measurable –detected by direct observation or other measuring devices Methods and data must be objective –no opinions or bias Scientists must be able to communicate the results of their experiment to others –Meetings, journals

19 19 Guidelines cont. Procedures must be repeatable –Other scientists can do the same procedure or experiment Must use an organized and systematic approach in gathering data

20 20 The Testing Method Reliability: a measure of consistency; must yield similar results on different testing occasions Validity: the degree to which a test measures what it is suppose to measure

21 21 A Theory is an explanation that integrates principles and organizes and predicts behavior or events. For example, low self-esteem contributes to depression. Theory

22 22 A Hypothesis is a testable prediction, often prompted by a theory, to enable us to accept, reject or revise the theory. People with low self-esteem are apt to feel more depressed. Hypothesis

23 23 Research would require us to administer tests of self-esteem and depression. Individuals who score low on a self-esteem test and high on a depression test would confirm our hypothesis. Research Observations

24 24 Research Process

25 25 Description Case Study A technique in which one person is studied in depth to reveal underlying behavioral principles. Is language uniquely human? Susan Kuklin/ Photo Researchers

26 26 Case Study A clinical study is a form of case study in which the therapist investigates the problems associated with a client. Clinical Study

27 27 METHODS cont. CASE-STUDY METHOD: –Study an individuals background forces that influence their behavior (family background, home life, neighborhood, school, etc.) –ADVANTAGE: Can exhibit individual differences and suggest hypotheses Can study phenomena you cannot manipulate Can generate hypotheses to be tested –DISADVANTAGE: Information comes from family, teachers and friends of individual being studied (biased?) Info. may be misleading Cant generalize nor replicate Observer bias could be present Cannot show causality Psychologists can guide patients into saying what they want hear

28 28 METHODS cont. INTERVIEWS: –One-on-one questioning –ADVANTAGE: Develop rapport, relaxed atmosphere, questions in advance/flexibility –DISADVANTAGE: getting rid of the personal prejudices of the interviewer, difficulty in expressing the results of an interview in exact terms

29 29 METHODS cont. QUESTIONNAIRE: –ADVANTAGES: Gather facts about individuals or opinions Answers can be treated statistically

30 30 METHODS cont. TESTS –I.Q. –Aptitude (A.S.V.A.B.) –Achievement (A.C.T., S.A.T., M.A.P.) –ADVANTAGES: more objective data than interviews and questionnaires Results can be expressed in statistical terms Scores can be compared with scores for large groups –DISADVANTAGES: Results do not give full and final answers to individual problems

31 31 Survey A technique for ascertaining the self-reported attitudes, opinions or behaviors of people usually done by questioning a representative, random sample of people.

32 32 Survey Reveals attitudes and behaviors of large sample of people Learn about behavior and mental processes that cannot be observed in the natural setting or studied experimentally

33 33 Limitations Limited generalization Replication sensitive to sample selected Give socially desirable answers Exaggerated answers to foul up results Different interviewers for different samples (gender, SES, ethnicity)

34 34 Limitations (cont.) Easy to bias by Wording Effect -Given the number of shootings in schools, should we regulate handguns? True or False -Cannot establish causal relationships

35 35 Survey Wording can change the results of a survey. Q: Should cigarette ads and pornography be allowed on television? (not allowed vs. forbid) Wording Effect

36 36 Survey A tendency to overestimate the extent to which others share our beliefs and behaviors. False Consensus Effect

37 37 Samples and Populations Example: Alf Landon defeated Franklin D. Roosevelt in 1936 poll (Roosevelt won by landslide) - surveyed voters by phone -during Great Depression Wealthy->phones>Republican

38 38 Samples Must accurately represent the population they are intended to reflect. Only representative samples allow us to generalize from research samples to populations.

39 39 Sample/Population Sample: The individuals who are studied; part of a population Population: a complete group of organisms or events Infer:Draw a conclusion

40 40 Problems in Generalizing Research sample (consider gender, age, ethnicity) Volunteer Bias

41 41 Volunteer Bias A source of bias or error in research that reflects the prospect that people who offer to participate in research studies differ systematically from people who dont.

42 42 Volunteer Bias More willing to disclose intimate information Volunteers have more spare time than nonvolunteers How do they differ from the population at large?

43 43 Problems with Generalization Demographic variables: -age -education -socioeconomic status -marital status -number of children -location

44 44 Survey Random Sampling If each member of a population has an equal chance of inclusion into a sample, it is called a random sample (unbiased). If the survey sample is biased, its results are not valid. The fastest way to know about the marble color ratio is to blindly transfer a few into a smaller jar and count them.

45 45 Question If scientists conducted research with a random sample of students from Valencia, would their sample represent the general U.S. population? Why or why not?

46 46 Naturalistic Observation Observing and recording the behavior of animals in the wild and recording self-seating patterns in a multiracial school lunch room constitute naturalistic observation. Courtesy of Gilda Morelli

47 47 METHODS NATURAL OBSERVATION: –Observing and recording the behavior of organisms in their natural environment. –ADVANTAGE: description of the way organisms behave in their surroundings –DISADVANTAGE: no information on how or why the behavior occurs

48 48 METHODS cont. DIRECTED OBSERVATION: –Involves observing behavior under controlled conditions in an experimental or a laboratory setting –ADVANTAGE: Allows for control of events and behaviors –DISADVANTAGE: Taking an organism from its natural environment may change its behavior

49 49 Descriptive Methods Case studies, surveys, and naturalistic observation describe behaviors. Summary

50 50 Assignment Form a hypothesis about human behavior and use the method of naturalistic observation to support/refute your hypothesis. Write what you observed and concluded. Ex: If there are sales, then more women than men will shop at malls. Due MONDAY SEPTEMEBER 15

51 51 longitudinal studies A psychologist studies the same group of people at regular intervals over a period of years to determine whether their behavior and/or feelings have changed and if so, how. Ex: Studying you when you were 5, then 10, then 15, then 20, then 25, then 30, etc…

52 52 cross-sectional studies. In this study, psychologists organize individuals into groups based on age. Then, these groups are randomly sampled, and the members of each group are surveyed, tested, or observed simultaneously. Single point in time (snapshot) Ex: IQ, memory, disease

53 53 Correlation When one trait or behavior accompanies another, we say the two correlate. Correlation coefficient Indicates direction of relationship (positive or negative) Indicates strength of relationship (0.00 to 1.00) r = Correlation Coefficient is a statistical measure of the relationship between two variables.

54 54 Correlational Method Examines the extent to which two or more variables are related and can predict one another.

55 55 Correlational Method Virtues: -reveals relations of variables outside the lab -replication possible Limitations: -cannot establish causal relationships because you do not manipulate the variables

56 56 Correlation Coefficient A number that varies between and Expresses the strength and direction (+/-) of the relationship between two variables The closer it is to 1.00 (regardless of +/-) the stronger the relationship

57 57 Positive Correlation A relationship between variables in which one variable increases as the other also increases Example: Hours of study and GPA

58 58 Positive Correlation A positive relationship means: As (A) increases, so does (B) Hours of study (A) is positively correlated with GPA (B)

59 59 Negative Correlation A relationship between two variables in which one variable increases as the other decreases. Example: Hours of TV and GPA

60 60 Negative Correlation A negative relationship means: As (A) increases, (B) decreases Number of hours of TV (A) has a negative relationship with GPA (B)

61 61 Correlation Research Correlational research may suggest but does not show cause and effect Often seems clear cut: Increase in Hours of study-> increase in GPA But could go other way: Students doing well in school are motivated to study more GPA-> Hours of study

62 62

63 63

64 64

65 65 Correlation Research Or some third factor (Confounding Variable): Achievement Motivation could cause both -> Hours of study -> GPA Test: length of marriage is correlated with male baldness. Does marriage cause baldness?

66 66 Perfect positive correlation (+1.00) Scatterplot is a graph comprised of points that are generated by values of two variables. The slope of the points depicts the direction, while the amount of scatter depicts the strength of the relationship. Scatterplots

67 67 No relationship (0.00) Perfect negative correlation (-1.00) The Scatterplot on the left shows a negative correlation, while the one on the right shows no relationship between the two variables. Scatterplots

68 68

69 69 Data Data showing height and temperament in people.

70 70 Scatterplot The Scatterplot below shows the relationship between height and temperament in people. There is a moderate positive correlation of

71 71 or Correlation and Causation

72 72 Illusory Correlation The perception of a relationship where no relationship actually exists. Parents conceive children after adoption. Confirming evidence Disconfirming evidence Do not adopt Disconfirming evidence Confirming evidence Adopt Do not conceive Conceive Michael Newman Jr./ Photo Edit

73 73 IMPORTANT Correlation does NOT mean Causation!!!

74 74 Given random data, we look for order and meaningful patterns. Order in Random Events Your chances of being dealt either of these hands is precisely the same: 1 in 2,598,960.

75 75 Order in Random Events Given large numbers of random outcomes, a few are likely to express order. Angelo and Maria Gallina won two California lottery games on the same day. Jerry Telfer/ San Francisco Chronicle

76 76 Experimentation Like other sciences, experimentation is the backbone of psychology research. Experiments isolate causes and their effects. Exploring Cause and Effect

77 77 Experimental Method A scientific method that seeks to confirm cause and effect relationships by introducing independent variables and observing their effects on dependent variables.

78 78 Experimental Method Treatment: in experiments, a condition received by participants so that its effects may be observed.

79 79 Many factors influence our behavior. Experiments (1) manipulate factors that interest us, while other factors are kept under (2) control. Effects generated by manipulated factors isolate cause and effect relationships. Exploring Cause & Effect

80 80 An Independent Variable is a factor manipulated by the experimenter. The effect of the independent variable is the focus of the study. For example, when examining the effects of breast feeding upon intelligence, breast feeding is the independent variable. Independent Variable

81 81 A Dependent Variable is a factor that may change in response to an independent variable. In psychology, it is usually a behavior or a mental process. For example, in our study on the effect of breast feeding upon intelligence, intelligence is the dependent variable. Dependent Variable

82 82 Experimental Research Manipulate the Independent Variable (IV) Holding all other variables constant Observe the impact on the Dependent Variable (DV)

83 83 DRY MIX DependentManipulate ResultIndependent YX Operational Definition of DV-the parameters of how we measure things

84 84 Experimental Research Example: Aggression & Alcohol (IV): Alcohol -administered at different levels, doses (DV):Aggressive behavior

85 85 Experimental Research Experimental Participants: Partake of the treatment (example: members would ingest alcohol) Control Group: do not take the treatment (example: do not ingest alcohol) *** all other conditions are held constant (helps determine cause and effect)

86 86 Placebo Sugar pill often results in the behavior that people expect. Physicians now and then give sugar pills to demanding, but healthy people. They often report they feel better.

87 87 Placebo Example: Tonic water & alcohol Giving participants placebo (tonic water) but they think they are drinking alcohol We can conclude that changes in behavior stem from their beliefs about alcohol, not the alcohol itself.

88 88 Blinds and Double Blinds Expectations: -Aggression may not have resulted from alcohol because individuals may have expectations of the effects of alcohol. -People act in stereotypical ways when they believe they have been drinking alcohol. (people may become less anxious in social situations, more aggressive, or more sexually aroused)

89 89 Blind Well-designed experiments control for the effects of expectations by creating conditions under which participants are unaware of the treatment.

90 90 Double-Blind Studies A study in which neither the participants nor the persons measuring results know who has received the treatment.

91 91 In evaluating drug therapies, patients and experimenters assistants should remain unaware of which patients had the real treatment and which patients had the placebo treatment. Evaluating Therapies Double-blind Procedure

92 92 Assigning participants to experimental (Breast-fed) and control (formula-fed) conditions by random assignment minimizes pre-existing differences between the two groups. * Different from random sampling Evaluating Therapies Random Assignment

93 93 Experimentation A summary of steps during experimentation.

94 94 Comparison Below is a comparison of different research methods.

95 95 Statistical Reasoning Statistical procedures analyze and interpret data allowing us to see what the unaided eye misses. Composition of ethnicity in urban locales

96 96 Describing Data A meaningful description of data is important in research. Misrepresentation may lead to incorrect conclusions.

97 97 Measures of Central Tendency Mode: The most frequently occurring score in a distribution. Mean: The arithmetic average of scores in a distribution obtained by adding the scores and then dividing by the number of scores that were added together. Median: The middle score in a rank-ordered distribution.

98 98 M&Ms Activity 1)Quantify (count) the data within the bag=total M&Ms 2)Sort them according to color (10 orange, 3 red, 4 green, etc…)

99 99 M&M Activity 3) Determine the groups quantity (total) 4) Find the groups mean 5) Find individual mode 6) Find groups mode Bi-modal=> two categories with the same mode

100 100 Measures of Central Tendency A Skewed Distribution

101 101 Measures of Variation Range: The difference between the highest and lowest scores in a distribution. Standard Deviation: A computed measure of how much scores vary around the mean.

102 102 M&M Activity 7)Find the range of groups bag quantity *Highest # of m&ms-lowest # of m&ms 8) Find the range of colors in individual bag 9) Calculate Standard Deviation

103 103 Standard Deviation 1)Determine the mean 2)Subtract the mean from every number to get the list of deviations (negative numbers are ok) 3)Square the resulting list of numbers 4)Add up all the resulting squares to get their total sum 5)Divide your result by one less than the number of items in the list 6)To get the SD, take the square root of the resulting number

104 104 Practice Standard Deviation your list of numbers: 1, 3, 4, 6, 9, 19 1) mean: ( ) / 6 = 42 / 6 = 7 2) list of deviations: -6, -4, -3, -1, 2, 12 3) squares of deviations: 36, 16, 9, 1, 4, 144 4) sum of deviations: = 210 5) divided by one less than the number of items in the list: 210 / 5 = 42 6) square root of this number: square root (42) = about 6.48

105 105 Standard Deviation

106 106 Making Inferences A statistical statement of how frequently an obtained result occurred by experimental manipulation or by chance.

107 107 Making Inferences Representative samples are better than biased samples. Less variable observations are more reliable than more variable ones. More cases are better than fewer cases. When is an Observed Difference Reliable?

108 108 Making Inferences When sample averages are reliable and the difference between them is relatively large, we say the difference has statistical significance. For psychologists this difference is measured through alpha level set at 5 percent (.05) When is a Difference Significant?

109 109 FAQ Q1. Can laboratory experiments illuminate everyday life? Ans: Artificial laboratory conditions are created to study behavior in simplistic terms. The goal is to find underlying principles that govern behavior.

110 110 FAQ Q2. Does behavior depend on ones culture? Ans: Even when specific attitudes and behaviors vary across cultures, as they often do, the underlying processes are much the same. Ami Vitale/ Getty Images

111 111 FAQ Q3. Does behavior vary with gender? Ans: Yes. Biology determines our sex, and culture further bends the genders. However, in many ways woman and man are similarly human.

112 112 FAQ Q4. Why do psychologists study animals? Ans: Studying animals gives us the understanding of many behaviors that may have common biology across animals and humans. D. Shapiro, © Wildlife Conservation Society

113 113 FAQ Q5. Is it ethical to experiment on animals? Ans: Yes. To gain insights to devastating and fatal diseases. All researchers who deal with animal research are required to follow ethical guidelines in caring for these animals.

114 114 FAQ Q6. Is it ethical to experiment on people? Ans: Yes. Experiments that do not involve any kind of physical or psychological harm beyond normal levels encountered in daily life may be carried out.

115 115 FAQ Q7. Is psychology free of value judgments? Ans: No. Psychology emerges from people who subscribe to a set of values and judgments. © Roger Shepard

116 116 FAQ Q8. Is psychology potentially dangerous? Ans: It can be, but it is not. The purpose of psychology is to help humanity with problems such as war, hunger, prejudice, crime, family dysfunction, etc.

Download ppt "1 Thinking Critically with Psychological Science Chapter 1."

Similar presentations

Ads by Google