The Scientific Method

1. The Scientific Method

3. Key Issues in Human Development 1- Heredity and Environment Heredity-oriented theories assume an important role of underlying biological structures. They point out that specific genes may underlie development and behavior. Environmental explanations focus on the individual’s experience pertaining to thinking, health, and social factors

4. Key Issues in Human Development • Heredity and environment interact, but theorists still disagree over the relative contributions of each and the manner of their interaction. • The position that the theorists take on this question determines the direction and nature of their research

5. Key Issues in Human Development 2- Maturation and Learning Maturation refers to biological processes. Learning refers to change over time related to practice or experience. When development is considered in terms of maturation and learning, the emphasis is on time. Example: How is the biological event of menopause affected by a woman’s lifestyle (experience)?

6. Key Issues in Human Development 3- Critical Versus Sensitive Periods Optimal periods during which certain types of learning occur best Readiness refers to reaching a maturational point at which a specific behavior can be learned Examples: The effects of certain diseases during pregnancy Acquiring a second language during an early age The critical time span several hours after birth during which goslings become bonded to the mother (imprinting)

7. The Scientific Method

8. What Makes Research Scientific? 1- Precision 2- Skepticism 3- Reliance on Empirical Evidence 4- The Principle of Falsifiability 5- Openness? Replication

9. Science becomes dangerous only when it imagines that it has reached its goal. (George Bernard Shaw)

10. Issues in Data Collection 1- Sampling Random Sampling Representative Sample 2- Reliability The degree of consistency with which a test or scale measures something. 3- Validity The extent to which a test or scale measures what it is supposed to measure

11. Validity 1- Internal Validity What happened to the experimental group actually caused the new behavior. 2- External Validity The extent to which an experiment corresponds to what happens in the real world 3- Construct

13. How Do Psychologists Observe and Describe Behavior? 1- Descriptive Method 2- Correlational Studies 3- Experimental Method

14. 1- Descriptive Methods Approaches that primarily involve the observation and description of behavior Methods of Studying Behavior

15. Methods of Studying Behavior 2- Correlational Studies Examine the relationship between two variables to determine whether they are associated or correlated

16. 3- Experimental Methods Approaches that go beyond description and attempt to determine what causes what in development and behavior Methods of Studying Behavior

17. Descriptive Approaches 1- Case Studies 2- Systematic Observation 3- Questionnaires and Surveys 4- Psychological Testing 5- Developmental Research Design

18. Case Study Sometimes are called baby biographies They involve extensive interviews with a particular individual or a small group of individuals Drawbacks 1- The lack of standardization 2- Reliance on language

19. Naturalistic Observation Occurs in a natural setting such as studying apes in the wild or people in bars Laboratory Observation The psychologist has more control One shortcoming is that the presence of researchers and special equipment may cause subjects to behave differently Systematic Observation

20. Questionnaires and Surveys Interview that ask people directly about their experiences, attitudes, or opinions Drawbacks The difficulty of getting a representative sample When dealing with volunteers, we may have volunteer bias

21. Psychological Tests Sometimes called assessment instruments Are procedures used for measuring and evaluating personality traits, emotional states, aptitudes, interests, abilities, and values

22. Objective Tests Also called Inventories Measure beliefs, feelings, or behaviors of which the individual is aware Have more reliability and validity Projective Tests Designed to tap unconscious feelings or motives Psychological Testing

24. Projective Tests 1- Association Techniques The Rorschach Test The Word Association Test 2- Completion Techniques Sentence Completion Tests Rosenzweig Picture Frustration Study

25. The Rorschach Projective Test

26. Projective Tests 3- Construction Techniques The Thematic Apperception Test (TAT) The Picture Projective Test (PPT) 4- Expression Techniques The Draw-a-person Test The House-tree-person Test

27. Developmental Research 1- The Longitudinal Design 2- The Cross-Sectional Design 3- The Sequential-Cohort Design

28. 1- The Longitudinal Design A group of individuals is studied repeatedly at different points in the lifespan Drawbacks: a. Large investments in time and money b. Some subjects drop out or die c. Some subjects become testwise d. Changes in individuals may be due to the time of measurement rather than development

29. 2- The Cross-Sectional Design Compares individuals of different ages at one point of time Drawbacks: a. It tells us more about age groups than about development within the individuals b. The cohorts differ not only in chronological age but also in the time period in which they were born

30. 3- The Sequential-Cohort Design A mix of the two types of research Example: Studying a group of 4-year-olds, a group of 8-year-olds, and a group of 12-year-olds each 2 years comparing them longitudinally and cross-sectionally

31. The Experimental Method in Psychology

32. Defining Psychology Psychology is the scientific study of behaviorand mental processes and how they are affected by an organism’s physical state, mental state, and external environment.

33. Correlational Study by Craig Anderson & Karen Dill (2000) The Effects of playing violent video games on behavior, especially aggressive behavior

34. Correlational Study by Anderson and Dill (2000) Method A correlational study based on questionnaires and personality measures administered to a large number of college students

35. Correlational Study by Anderson and Dill (2000) Results Analysis of data indicated that playing violent video games was strongly and positively correlated with two factors: a. Aggressive delinquent behavior in real life b. Aggressive personality characteristics

36. Plausible Causes for Aggressive Behavior

37. Plausible Causes for Aggressive Behavior

38. Plausible Causes for Aggressive Behavior

39. Correlational Studies Examine the relationship between two variables to determine whether they are associated or correlated Establishing a correlation between 2 variables does not indicatecausality

40. Experimental Methods Anderson and Dill (2000) The Effects of playing violent video games on behavior, especially aggressive behavior

41. Hypothesis Playing violent video games would increase aggressive behavior

44. The Outcome of the Experiment The results confirmed that participants who played a violent video game behaved more aggressively than participants who played a nonviolent video game.

45. Experimental Methods

46. Experimental Methods They tell us about cause and effect The investigator manipulates one set of variables (independent variables)and observes their influence on another set of variables(dependent variables) To establish causality, experimenters compare different groups, experimental groups and control groups.

47. Experimental Design Questions: Who are the subjects? What is the independent variable? What is the variable that is going to change because of manipulation? What is the dependent variable? If there were changes in behavior, what was the causative agent? What was the outcome of the experiment in one sentence?

48. Ethics in Research 1- Freedom from Harm 2- Informed Consent 3- Use of Deception 4- Maintenance of Privacy

49. Hypothesis Correlational studies Experimental method Independent variable Dependent variable Experimental group Control Group Validity Construct Reliability Representative sampling Causality Understand these Terms

50. Design Your Own Research 1- You want to examine the effect of watching violent movies on the behavior of children, what design are you going to use, cross-sectional, longitudinal, or sequential-cohort design? 2- What is your hypothesis? 3- How many groups are you going to have? Why? 4- What is the population you are going to experiment on? How are you going to select your sample?