RESEARCH METHODS: PSYCHOLOGY AS A SCIENCE

Transcription

1 RESEARCH METHODS: PSYCHOLOGY AS A SCIENCE

2 TODAY S OBJECTIVE Explain basic methods of psychological research.

3 IMPORTANT KEY TERMS Variable: anything that can change Theory: broad idea or set of closely related ideas that attempt to explain observations Hypothesis: Educated guess derives logically from a theory

4 CRITICAL THINKING Scientific attitude encourages critical thinking The process of assessing claims and making judgments on the basis of well-supported evidence Examples of critical thinking questions: What am I being asked to believe or accept? What evidence is available to support the assertion? Are there alternative ways of interpreting the evidence? What additional evidence would help to evaluate the alternatives? What conclusions are most reasonable?

5 GUIDELINES FOR STUDYING BEHAVIOR SCIENTIFICALLY 1. Behavior must be measurable 2. Methods and data must be objective 3. Procedures must be repeatable 4. Scientists must be able to communicate the results of the experiment to others 5. Experimenters must use an organized and systematic approach in gathering data

6 GOALS OF PSYCHOLOGICAL RESEARCH Description of social behavior Ex: Are people who grow up in warm climates different from those in cold climates? Establish a relationship between cause & effect Ex: Does heat cause higher amounts of aggression? Develop theories about why people behave the way that they do Ex: We dislike Duke students to feel better about ourselves Application Creating effective therapeutic treatments, more successful negotiation tactics, and greater understanding amongst groups of people

7 Empirical EMPIRICAL RESEARCH Knowledge based on direct observation Publicly (confirmable) observable behavior Theory Set of ideas which try to explain what we observe Goal is to find support OR disprove We can never prove!!

8 TYPES OF RESEARCH Commonly use 3 types of research: 1. Descriptive 2. Correlational 3. Experimental

9 DESCRIPTIVE RESEARCH Simplest method of scientific inquiry About describing some phenomenon Ex: defining what this thing is, how often does it occurs (prevalence), etc. By itself, can only achieve descriptive stats cannot support/disprove theory Types of Descriptive Research: 1. Observation 2. Surveys and Interviews 3. Case Studies

10 1. Observation: DESCRIPTIVE RESEARCH TYPES - Covert: secret observation - Overt: known but without disturbing normal behavior 2. Surveys and Interviews: ask people what they think, their opinions, etc. - Often the best and quickest way to gain information - Often done after an OVERT observation 3. Case Studies: in-depth look at a single individual - Provides a dramatic, detailed look of a person s lives

11 CORRELATIONAL RESEARCH Tells us about the relationship between two variables Named for the statistical technique used to analyze the data Degree of the relationship is expressed numerical value = coefficient (r) The number expressed the strength of the relationship Value of the coefficient always fall between and The closer the number is to +1.00, the stronger the relationship The sign (+ or -) expresses the direction of the relationship Positive (+) means that as one variable increases, the other also increases = Same direction Negative (-) means that as one increases, the other decreases = Opposite direction ZERO correlation means that there is no systematic relationship between the two variables

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13 IMPORTANT TO REMEMBER CORRELATION DOES NOT EQUAL CAUSATION!! Correlation only means that two variables change together Being able to predict one event based on the occurrence of another event does not necessarily tell us anything about the cause of either event!! Remember: there are other factors that may have not been measured

14 EXPERIMENTAL RESEARCH Mostly done in highly controlled conditions (LAB) Experiment: carefully regulated procedure in which the researcher manipulates one or more variables that are believed to influence some other variables. Variables: anything that can be changed Independent Variable: manipulated experimental factor, affects the dependent var. (cause) Dependent Variable: affected by the indep. var. Usually what is being studied (effect) What (i.d) is affecting what (d.)? Confederate: Pseudo subject in a social exp.

15 Y SCIENTIFIC METHOD 1. OBSERVE SOME PHENOMENON / SELECT A TOPIC 2. FORMULATE HYPOTHESIS AND PREDICTIONS 3. TESTING THROUGH EMPIRICAL RESEARCH 4. DRAWING CONCLUSIONS 5. EVALUATING THE THEORY

16 1. Select a topic THE METHOD Good theory: broad idea or set of closely related ideas that attempt to explain observations Has predictive power Is simple & straightforward 2. Formulate hypotheses Hypothesis: specific statement of expectation derived from theory State the relationship between two variables Variable: can be any event, characteristic, condition, or behavior

17 TESTING 3. Has to be done through EMPIRICAL RESEARCH *Knowledge based on direct observation*

18 THE METHOD 4. Drawing conclusions Based on data analysis Data needs to be able to be REPLICATED for the theory to be proven or disproven. 5. Evaluating the Theory Never really ends Others will look at the theory and replicate and retest

19 EXPERIMENTATION Replication of studies is essential in science. (Other researchers can retest your hypothesis for procedural and outcome validity.) Psychological research should have ecological validity, focusing on processes that occur in real-life environments.

20 EXPERIMENTATION A good experiment has reliability and validity. Reliability means the consistency of measurements. (replicable) Validity means the accuracy of measurements.

21 TYPES OF GROUPS Experiments can involve one or more groups Researchers manipulate (change) the indep. var. to create the groups Experimental Group: made up of those who are exposed to the change the indep. var. presents Control Group: made up of those who are NOT exposed to the change Treated the exact same way though, everything except the change Provides a comparison against the indep. var. Placebo: harmless substance that has no physiological effect

22 EXAMPLE #1 A researcher wanted to study the effects of sleep deprivation on physical coordination. The researcher selected 25 year-old male college students and deprived some of the subjects to either 24, 36, or 45 hours of sleep. In the present study the independent variable was: a) the length of time the subjects were deprived of sleep. b) the age of the subjects. c) the gender of the subjects. d) the physical coordination skills of the subjects. In the present study the dependent variable was: a) the length of time the subjects were deprived of sleep. b) the age of the subjects. c) the gender of the subjects. d) the physical coordination skills of the subjects. ANSWER: Independent variable was the length of time the subjects were sleep deprived. Dependent variable was the physical coordination skills of the subjects.

23 EXAMPLE #2 An investigator had 60 subjects watch a videotaped re-enactment of a bank robbery. Half of the subjects were asked by a police investigator to recall the event, while the remaining subjects were interviewed by a police investigator while they were hypnotized. In the present study the independent variable was: a) whether a police investigator was used. b) whether subjects were hypnotized. c) how much subjects recalled. d) what subjects watched. In the present study the dependent variable was: a) whether a police investigator was used. b) whether subjects were hypnotized. c) how much subjects recalled. d) what subjects watched. ANSWER: Independent variable was whether the subjects were hypnotized. Dependent variable was how much subjects recalled.

24 PROBLEMS Experimenter Bias: occurs when experimenter s expectations influence the outcome of the research Double-blind design: Study in which neither the experimenter nor the participant knows if the subject is in the experimental or control group Hawthorne Effect: People tend to behave differently when they know they are being watched Placebo Effect: Occurs when participant s expectations, rather than the treatment, influence the outcome Single-blind design: Study in which participant is unaware of placement in experimental or control group

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