Research Methods

Research Methods – True or False? Human intuition is remarkably accurate and free from error. False Most people seem to lack confidence in the accuracy of their beliefs. Most people suffer from unrealistically low self-esteem. The opinions of 1500 randomly selected people can provide a very accurate picture of the opinions of an entire nation. True Research suggests that students spend more than 28% of their waking hours in conversation.

The scientific finding that depressed people tend to have low self-esteem proves that depression causes people to be down on themselves. False The purpose of the experiment is to re-create behaviors exactly as they occur in everyday life. Males and females exhibit similar overall intelligence and well-being. True Under ethical and legal guidelines, animals used in experiments rarely experience pain. As a science, psychology is objective and value-free.

Let’s Make a Deal! Calculate the percentage of wins from switching. Correct Answer Participants Choice Stay/Switch Win/Lose A B SWITCH WIN Calculate the percentage of wins from switching. For example, if you switched a total of 10 times and won 7, your win rate would be 70% Calculate the percentage of wins from staying. If you stayed 10 times and won 5 of those times, your win rate would be 50%

Reasoning Fallacies Hindsight bias Tendency to believe, after learning an outcome, that one would have foreseen it The “I knew it all along” phenomenon Ex: After the Packers lost on Sunday, people thought, “I knew all along they’d lose.” – even if they didn’t

How long would it take you to figure out these word scrambles? wreat water etryn entry grabe barge Unscramble this word: ochsa

Overconfidence Tendency to think we know more than we do EX: Thinking you did better on a quiz than you actually did

Examples of Overconfidence “There is no reason for anyone to have a computer in their home.” ~Ken Olson, president of Digital Equipment Company, 1977 “Heavier-than-air flying machines are impossible.” ~Lord Kelvin, British mathematician, 1895 “Man will never reach the moon, regardless of all future scientific advances.” ~Lee Deforest, inventor of the vacuum tube, 1957 “Nuclear powered vacuum cleaners will probably be a reality within 10 years.” ~Alex Lewyt, manufacturer of vacuum cleaners, 1955

Astrology E = Aries (March 21 – April 19) B = Taurus (April 20 – May 20) C = Gemini (May 21 – June 21) A = Cancer (June 22 – July 22) F = Leo (July 23 – Aug 22) D = Virgo (Aug 23 – Sept 22) K = Libra (Sept 23 – Oct 22) H = Scorpio (Oct 23 – Nov 21) I = Sagittarius (Nov 22 – Dec 21) L = Capricorn (Dec 22 – Jan 19) J = Aquarius (Jan 20 – Feb 18) G = Pisces (Feb 19 – March 20)

Ethics In conducting an experiment, psychologists must Obtain informed consent of participants Protect them from harm and discomfort Treat info about participants confidentially Fully explain research afterward

Testing hypotheses with descriptive methods Case study - studies one person in depth in hopes of revealing universal principles EX: studying a patient with a specific mental disorder

Survey - uses a representative sample of people to estimate attitudes or reported behaviors of a whole population Population - all the cases in a group being studied from which samples may be drawn Random sample - every member of a population has an equal chance of inclusion

A Random Sample

Random Sampling At the end of the first two weeks of the baseball season, newspapers start publishing the top ten batting averages. The leader after the first two weeks normally has a batting average of .450 or higher. Yet no major league baseball player has ever finished the season with a better than .450 average. What do you think is the explanation for the fact that batting averages are higher earlier in the season?

Importance of Sample Size Imagine you are a golfer of above-average ability and that you have the opportunity to play the greatest golfer in the world. If you want to maximize your slim chance of winning, how much golf would you elect toplay, g iven the choices of 1, 18, 36 or 72 holes?

A certain town is served by two hospitals A certain town is served by two hospitals. In the larger hospital about 45 babies are born each day, and in the smaller hospital about 15 babies are born each day. Although the overall proportion of boys is about 50%, the actual proportion at either hospital may be greater or less than 50% on any day. At the end of a year, which hospital will have the greater number of days on which more than 60% of the babies born were boys? The larger hospital The smaller hospital Neither – the number of days will be about the same (within 5% of each other)

Examples of Poorly Worded Questions “Does Michigan spend too much, too little or the right amount on prisons and corrections?” 38.4% said too much; 35.4% said not enough When asked whether spending $1.3 billion on prisons and corrections was too much, too little or the right amount, 54.9% said too much, 14% said not enough American Museum of Natural History survey found: 77% of people were interested in plants and trees but only 39% were interested in botany 48% were interested in fossils but only 39% were interested in paleontology 42% were interested in rocks and minerals, but 53%were interested in geology

“The problems faced by Blacks were brought on by Blacks themselves.” When interviewed by Whites, 62% of White respondents agreed When interviewed by Blacks, 46% agreed When a New York Times/CBS News poll asked people if the favored an amendment “prohibiting abortions”, a majority opposed it When asked whether they favored “protecting the life of the unborn child,” 20% switched sides

The worst poll question of all time (1937 British Gallup Poll question): “Are you in favor of direct retaliatory measures against Franco’s piracy?” Problems: It is not balanced. It assumes knowledge. It does not use every day language. It employs a pejorative (a word/phrase that has negative connotation). It is vague.

Naturalistic observation - observing and recording behavior in a natural environment Studying gorillas in the wild or high school behavior in the lunch room Advantage: Can observe someone in his natural environment Disadvantages: Reactivity subject’s behavior is different when the person knows he is being observed than it would otherwise be Single cases may be misleading

Correlational studies Measure how closely two things vary together and thus how well either one predicts the other Graphed on a scatterplot and measured with a correlation coefficient Positive = two sets of scores rise or fall together Negative = two sets of scores relate inversely zero = weak correlation

CORRELATION DOES NOT PROVE CAUSATION EX: Self-esteem and depression are negatively correlated. Which is causation? Is a third factor (heredity, age) to blame?

Examples “People who floss their teeth more often live longer.” “The number of drownings in the U.S. rises and falls during the year, along with the amount of ice cream sold each month.” People who often ate Frosted Flakes as children had half the cancer rate of those who never ate the cereal. Conversely, those who often ate oatmeal as children were four times more likely to develop cancer than those who did not.

Illusory correlation: The perception of a relationship where none exists EX: It always rains after you wash your car.

Consider a random coin flip… If someone flipped a coin six times, which of the following sequences of heads (H) and tails (T) would be most likely? HHHTTT HTTHTH HHHHHH

Correlation examples - which are positive and which are negative? The more your children watch TV, the less they read. Negative correlation The more sexual content teens see on TV, the more likely they are to have sex. Positive correlation The longer children are breast-fed, the greater their later academic achievement. The more often adolescents eat breakfast, the lower their body mass.

Blue Brown Green Orange Red Yellow Actual 24% 13% 16% 20% 14% Predicted % Observed Frequency Actual 24% 13% 16% 20% 14%

Experimentation: in psychology, a study where variables are manipulated to determine a casual outcome Random assignment - assigning participants to experimental and control groups by chance Double blind procedure - neither the research participants nor the research staff know whether participants have received the treatment or a placebo

Placebo effect - experimental results caused by expectations alone EX: A drug/treatment works simply because the participant believes it will

EXPERIMENTAL EXAMPLE Experimental terms using the hypothesis: Breast feeding increases intelligence Experimental group - group exposed to treatment Babies who are breastfed Control group - group not exposed to treatment Babies who are bottle fed

Independent variable (IV) - experimental factor that is manipulated Breast fed or bottle fed Confounding variable - factor other than the IV that might produce an effect in an experiment Environment, diet, wealth Dependent variable - outcome factor; variable that may change in response to manipulations of the IV Intelligence

Statistical significance - observed difference is likely not due to chance variation between the samples

Practice Experiment: To test the effect of perceived ethnicity on the availability of a rental house, Adrian Carpusor and William Loges (2006) sent identically worded e-mail inquiries to 1115 Los Angeles-area landlords. The researchers varied the ethnic connotation of the sender’s name and tracked the percentage of positive replies. “Patrick McDougall,” “Said Al-Rahman,” and “Tyrell Jackson” received, respectively, 89%, 66% and 56% invitations. What is the independent variable? Ethnicity related names What is the dependent variable? Positive response rate

How could these proverbs be tested? It takes four hours to come down from your last cup of coffee. Wearing dark clothes on the bottom and light clothes on the top is usually more visually appealing than the reverse. As family income rises, the ratio of women’s shoes to men’s shoes increases accordingly. Don’t change your first guess on a multiple choice test.