Psychological Science, 3rd Edition Michael Gazzaniga Todd Heatherton Diane Halpern

1. Psychological Science, 3rd EditionMichael Gazzaniga Todd Heatherton Diane Halpern

2. Research Methodology 2

3. Questions to Consider: What Is Scientific Inquiry? What Are the Types of Studies in Psychological Research? What Are the Data Collection Methods of Psychological Science? How Are Data Analyzed and Evaluated?

4. Learning Objective Explain the differences among theories, hypotheses, and research.

5. What Is Scientific Inquiry? • The scientific method depends on theories, hypotheses, and research • Unexpected findings can be valuable

6. The Scientific Method Depends on Theories, Hypotheses, and Research • The four goals of psychological science are: • describe (what) • predict (when) • control (what causes) • explain (why)

7. The Scientific Method Depends on Theories, Hypotheses, and Research • Scientific inquiry relies on objective methods and empirical evidence to answer testable questions • Interconnected ideas or models of behavior (theories) yield testable predictions (hypotheses), which are tested in a systematic way (research) by collecting and evaluating evidence (data)

8. The scientific method reflects a cyclical relationship among a theory, a testable hypothesis (or testable hypotheses) derived from the theory, research conducted to test the hypothesis, and adjustments to the theory as findings prompt reevaluation. A good theory evolves over time, and the result is an increasingly accurate model of some phenomenon.

9. Unexpected Findings Can Be Valuable • Unexpected discoveries sometimes occur • Only researchers who are prepared to recognize their importance will benefit from them • Thorsten Wiesel and David Hubel

10. What Are the Types of Studies in Psychological Research? • Descriptive Studies Involve Observing and Classifying Behavior • Correlational Designs Examine How Variables Are Related • An Experiment Involves Manipulating Conditions • Critical Thinking Skill: Identifying the Need for Control Groups • Random Assignment Is Used to Establish Equivalent Groups • Critical Thinking Skill: Recognizing That Large Samples Generate More Reliable Results Than Small Samples

11. Learning Objectives List the advantages and disadvantages of different research methods Explain why random assignment is important when designing experiments

12. What Are the Types of Studies in Psychological Research? • There are three main types of studies in psychological research: descriptive, correlational, and experimental

13. Descriptive Studies Involve Observing and Classifying Behavior • Researchers observe and describe naturally occurring behaviors to provide a systematic and objective analysis • Two types of descriptive studies: naturalistic observation and participant observation

14. Descriptive Studies Involve Observing and Classifying Behavior • Observer Bias • Scientists must guard against errors in observation due to the observer’s expectations • Experimenter expectancy effect

16. Correlational Designs Examine How Variables Are Related • Correlational studies examine how variables are naturally related in the real world • Cannot be used to establish causality or the direction of a relationship • Third variable problem

17. An Experiment Involves Manipulating Conditions • An experiment is a study in which the researcher manipulates one variable to examine the variable’s effect on a second variable

18. An Experiment Involves Manipulating Conditions • Researchers control the variations in the conditions that the participant experiences (independent variables) and measure the outcomes (dependent variables) to gain an understanding of causality • Need a control group to know if the experiment had an effect

20. Critical Thinking Skill • It is important to recognize the need for control groups and to understand why large samples provide more reliable data than small samples • Divorce and money • Children’s educational products

21. Random Assignment Is Used to Establish Equivalent Groups • How do you select people to study? • The group you want to know about is the population • The subset of people who are studied is the sample

22. For the results of an experiment to be considered useful, the participants should be representative of the population. The best method for making this happen is random sampling, but most of the time researchers are forced to use a convenience sample. Random assignment is used when the experimenter wants to test a causal hypothesis.

23. Random Assignment Is Used to Establish Equivalent Groups • Random sampling allows for the best representation of the population • Selection bias • Random assignment

24. For the results of an experiment to be considered useful, the participants should be representative of the population. The best method for making this happen is random sampling, but most of the time researchers are forced to use a convenience sample. Random assignment is used when the experimenter wants to test a causal hypothesis.

25. What Are the Data Collection Methods of Psychological Science? • Observing Is an Unobtrusive Strategy • Case Studies Examine Individual Lives and Organizations • Asking Takes a More Active Approach • Response Performance Measures Information Processing • Body/Brain Activity Can Be Measured Directly • Research with Animals Provides Important Data • There Are Ethical Issues to Consider

26. Learning Objectives Provide examples of data collection methods that are appropriate for different research questions. Identify ethical issues and explain their importance.

27. What Are the Data Collection Methods of Psychological Science? • There are five basic data collection methods: • Observational techniques and case studies • Asking participants • Response performance • Measuring brain activity • Using animal models

28. Observing Is an Unobtrusive Strategy • Data collected by observation must be defined clearly and collected systematically. • Bias may occur in the data because the participants are aware they are being observed or because of the observer’s expectations.

29. Case Studies Examine Individual Lives and Organizations • Case Studies: • Intensive examinations of individual lives and organizations • Can be useful for examining an unusual participant or unusual research question • But interpretation can be subjective

30. Asking Takes a More Active Approach • Surveys, questionnaires, and interviews can be used to directly ask people about their thoughts and behaviors • Self-report data may be biased by the respondents’ desire to present themselves in a particular way (e.g., smart, honest) • Culturally sensitive research recognizes the differences among people from different cultural groups and from different language backgrounds

31. Response Performance Measures Information Processing • Response performance takes three basic forms: • Reaction times • Response accuracy • Stimulus judgments

34. Body/Brain Activity Can Be Measured Directly • Electrophysiology: • Often using an electroencephalograph (EEG) • Measures the brain’s electrical activity. • Different behavioral states produce different and predictable EEG patterns

35. Body/Brain Activity Can Be Measured Directly • Brain imaging: • Measure changes in rate of blood flow • Positron emission tomography (PET) • Magnetic resonance imaging (MRI) • Functional magnetic resonance imaging (fMRI) • Researchers can monitor which brain areas are active when people perform particular tasks or experience particular events

36. Body/Brain Activity Can Be Measured Directly • Transcranial magnetic stimulation (TMS): • Disrupts normal brain activity, allowing researchers to infer the brain processing involved in particular thoughts, feelings, and behaviors

37. Research with Animals Provides Important Data • Research involving nonhuman animals provides useful, although simpler, models of behavior and of genetics • The purpose of such research may be to learn about animals’ behavior or to make inferences about human behavior

38. There Are Ethical Issues to Consider • Ethical research is governed by a variety of principles that ensure fair and informed treatment of participants • Institutional review boards (IRBs) • Informed consent • Risks of participation

39. How Are Data Analyzed and Evaluated? • Good Research Requires Valid, Reliable, and Accurate Data • Descriptive Statistics Provide a Summary of the Data • Correlations Describe the Relationships between Variables • Inferential Statistics Permit Generalizations

40. Learning Objectives Describe measures of central tendency and variability. Discuss the rationale for inferential statistics.

41. Good Research Requires Valid, Reliable, and Accurate Data • Data must be meaningful (valid) and its measurement reliable (i.e., consistent and stable) and accurate

42. Good data should be valid (addressing the research question), reliable (consistent over time, no matter when or how the data are collected), and accurate (free from error). Random error occurs when the degree of error varies each time; systematic error occurs when the measurement has the same degree of error each time.

43. Good data should be valid (addressing the research question), reliable (consistent over time, no matter when or how the data are collected), and accurate (free from error). Random error occurs when the degree of error varies each time; systematic error occurs when the measurement has the same degree of error each time.

44. Descriptive Statistics Provide a Summary of the Data • Measures of central tendency and variability are used to describe data • Central tendency indicates statistical averages across sets of numbers • Standard deviation indicates how widely numbers are distributed about an average

45. Descriptive statistics are used to summarize a data set and to measure the central tendency and variability in a set of numbers.

46. Descriptive statistics are used to summarize a data set and to measure the central tendency and variability in a set of numbers.

47. Correlations Describe the Relationships between Variables • A correlation is a descriptive statistic that describes the strength and direction of the relationship between two variables • Correlations close to zero signify weak relationships; correlations near +1 or –1 signify strong relationships.

48. Scatterplots are graphs that illustrates the relationship between two variables. In general, according to this scatter plot, the more women worked, the more they wanted to have fun.

49. Correlations can have different values between 1 and 1, which reveal different kinds of relationships between two variables. The greater the scatter of values, the lower the correlation. A perfect correlation occurs when all the values fall on a straight line.

50. Inferential Statistics Permit Generalizations • Inferential statistics allow us to decide whether differences between two or more groups are probably just chance variations or whether they reflect true differences in the populations being compared