Psychology 1102: Chapter 2 Research Methods

Lecture Preview

n  What is good research design?

n  Explore the scientific method

n  Discuss the ethics of experimentation

n  Review statistics

n  Peer review

Facilitated Communication: A Cautionary Tale

n  Facilitated communication was a “revolutionary” treatment for autism (extraordinary claims)

n  Biklen (1990) thought that autism was primarily a motor disorder

n  Experimenter sat next to nonverbal child with autism and guided the child’s hand over a keyboard

n  Students seemed to make stunning progress in communication

                                 

Facilitated Communication: A Cautionary Tale

n  Students began making allegations of brutal sexual abuse

n  Dozens of controlled studies examined the phenomenon and found that the words came solely from the minds of the facilitators (much like a Ouija board)

n  It is still difficult for proper research findings to get into the mainstream psyche; some people still practice facilitated communication

The Beauty and Necessity of Good Research Design

n  But I know it works!

n  Often our impressions are wrong

n  Prefrontal lobotomy - example of what happens when we rely on our subjective impressions

n  Egaz Moniz won the Nobel prize for this procedure

n  Controlled studies showed it didn’t work

Prefrontal Lobotomy:  Psychosurgery and Reliance on Subjective Impressions

Heuristics and Biases:  How We Can Be Fooled

n  Heuristics - mental shortcuts or rules of thumb

n  Reduce the cognitive energy required to solve problems

n  We tend to oversimplify reality

n  Imagine yourself driving from Reno, Nevada, to San Diego, California - what compass direction would you take?

Common Heuristics Studied by Kahneman and Tversky

n  Representativeness - “like goes with like”

n  Base rate - how common a characteristic or behavior is in the general population

n  Base rate fallacy

n  Availability - “off the top of my head”

n  Estimating the likelihood of an occurrence based on the ease with which it comes to our minds

Cognitive Biases:  Systematic Errors in Thinking

n  Hindsight bias (“I knew it all along”) - tendency to overestimate how well we could have successfully forecasted known outcomes
(e.g., “I knew they were the perfect couple”)

n  Overconfidence - tendency to overestimate our ability to make correct predictions

n  These errors can lead to confidence in false conclusions

Scientific Method: A Toolbox of Skills

n  Allows us to test specific hypotheses derived from  broader theories of how things work

n  Theories are never “proven,” but hypotheses can be disconfirmed

n  Naturalistic Observation - watching behavior in real-world settings with

n  High degree of external validity - extent to which we can generalize our findings to the real world

n  Low degree of internal validity - extent to which we can draw cause-and-effect inferences

n  Case study designs

n  Depth is traded for breadth

n  Common with rare types of brain damage

n  Helpful in providing existence proofs, but can be misleading and anecdotal

n  Correlational designs

n  Correlation can vary from –1 to +1

n  0 means no relationship

n  Depicted in a scatterplot - each dot represents a single person’s data

n  Illusory Correlation - perception of a statistical association where none exists (e.g., crime and the full moon)

n  Correlation cannot determine causation - merely shows things are related or associated

Experimental Design:  What Makes a Study an Experiment?

n  Random assignment of participants to conditions

n  Experimental Group - receives the manipulation

n  Control Group - does not receive the manipulation

n  Independent Variable - experimenter manipulates

n  Dependent Variable - experimenter measures to see whether manipulation had an effect

n  Confounds - any difference between the experimental and control groups, other than the independent variable; makes independent variable effects uninterpretable

n  Cause and effect - possible to infer, with random assignment and manipulation of independent variable

Pitfalls of Experimental Design

n  Placebo effect - improvement resulting from the mere expectation of improvement

•      Subjects must be blind - unaware of whether they are in the experimental or control group

•      Placebos show many of the same characteristics as real drugs

n  Nocebo effect - harm resulting from the mere expectation of harm (e.g., voodoo doll phenomenon)

n  Experimenter expectancy effect - phenomenon in which researchers’ hypotheses lead them to unintentionally bias a study outcome

n  Clever Hans, the mathematical horse

n  Rosenthal’s undergrads and maze-bright, maze-dull rats

n  Double-blind design - neither researchers nor subjects know who is in the experimental or control group

n  Hawthorne effect - phenomenon in which participants’ knowledge that they’re being studied can affect their behavior

n  Demand characteristics - cues that participants pick up from a study that allow them to generate guesses regarding the researcher’s hypotheses

n  To minimize Hawthorne effects:

•      Covert observation

•      Participant observation

Asking People About Themselves and Others

n  Random selection - key to generalizability; ensures every person in a population has an equal chance of being chosen to participate

n  Evaluating Measures:

n  Reliability - consistency of measurement

n  Validity - extent to which a measure assesses what it claims to measure

n  A test must be reliable to be valid, but a reliable test can still be completely invalid

Self-Report Measures and Surveys

n  Self-report measures - questionnaires assessing a variety of characteristics (e.g., interests, traits)

n  Surveys - measure opinions, attitudes

n  Question phraseology is crucial

n  Pros

n  Easy to administer

n  Direct (self) assessment of person’s state

n  Cons

n  Accuracy is skewed for certain groups (narcissists)

n  Potential for dishonesty

n Response sets - tendencies of research subjects to distort their responses

n Positive impression management

n Malingering

Ratings Data:  How Do They Rate?

n  Halo effect - tendency of ratings of one positive characteristic to spill over to influence the ratings of other positive characteristics

n  Leniency effect - tendency of raters to provide ratings that are overly generous

n  Error of central tendency - an unwillingness to provide extreme ratings (low or high)

Ethical Issues in Research Design

n  Tuskegee Study (1932 to 1972)

n  African American men living in rural Alabama diagnosed with syphilis

n  U.S. Public Health Service never informed, or treated, the men

n  Merely studied the course of the disease: 28 men died of syphilis, 100 of related complications, 40 wives were infected,
19 children were born with it

n  In 1997, President Clinton offered a formal apology

Modern Ethical Guidelines

n  Institutional Review Board (IRB)

n  Informed Consent

n  Justification of deception

•      Milgram’s obedience study

n  Debriefing of subjects afterward

n  Animal Research

n  Institutional Animal Care and Use Committee (IACUC)

n  About 8% of psychological research uses animals

Statistics: The Language of Psychological Research

n  Descriptive statistics - numerical characteristics of the nature of the data set

n  Central tendency - where the group tends to cluster

•      Mean - average of all scores

•      Median - middle score in the data set

•      Mode - most frequent score in the data set

n  Dispersion - sense of how loosely or tightly bunched scores are

•      Range - difference between the highest and lowest scores

•      Standard deviation - measure of dispersion that takes into account how far each data point is from the mean

Statistics: The Language of Psychological Research

n  Inferential statistics - mathematical methods that allow us to determine whether we can generalize findings from our sample to the population

n  Statistical significance - finding would have occurred by chance less than 1 in 20 times

n  Practical significance - real-world importance

n  Statistical deceptions

n  Example:  Truncated line graphs

Evaluating Psychology in the Media

n  Most reporters are not scientists, so

n  Consider the source - tabloid vs. Discover

n  Beware of

•      Sharpening - exaggerating the central message of the study

•      Leveling - minimizing the less-central details

•      Pseudosymmetry - appearance of scientific controversy where none exists while purporting to provide “balanced coverage”

•       Example: Four paragraphs supporting ESP, four paragraphs against it