Non-experimental types of research.
Correlational Research Detects how well one variable predicts, not causes another variable. Does NOT say that one variable causes another. There is a positive correlation between income and years of education. Does that mean that having a higher income means you will have more education, or do people with more education have higher incomes?
Correlation Definition: an observation that two traits are related to each other Studies show that there is a strong correlation between how many books are present in a child s home and college completion rate. Do the books cause a person to complete college?
If self-esteem correlates with depression, there are still numerous possible causal links:
Types of Correlation Positive Correlation The variables go in the SAME direction. Negative Correlation The variables go in opposite directions. Studying and grades hopefully has a positive correlation. Heroin use and grades probably has a negative correlation.
If we find a correlation, what conclusions can we draw from it? Let s say we find the following result: there is a positive correlation between two variables, ice cream sales, and rates of violent crime How do we explain this?
The strength of relationships are measured using a correlation coefficient. The correlation coefficient is a number representing the strength and direction of correlation. Range is from -1 to +1 The relationship gets weaker the closer you get to zero.
What is a Correlation Coefficient
Perfect positive correlation No relationship, no correlation The strength of the relationship refers to how close the dots are to a straight line, which means one variable changes exactly as the other one does. Perfect negative correlation
Which correlation coefficient has the A..79 B. -.88 C..09 D. 3.6 E. -.05 strongest relationship? The B has the strongest. E has the weakest D. is invalid weakest? Which is a stronger correlation? -.13 or +.38 -.72 or +.59 -.91 or +.04
Correlation does not equal Causation! People who floss more regularly have less risk of heart disease. If this data is from a survey, can we conclude that flossing might prevent heart disease? Or that people with hearthealthy habits also floss regularly? People with bigger feet tend to be taller. Does that mean having bigger feet causes height?
Illusory Correlation Instructions You will see a series of statements, each describing a person performing some type of behavior. Each person belongs to either Group A or Group B. After all statements have been presented, you will respond with your impressions.
John visited a friend in the hospital.
Allen dented the fender of a parked car and didn t leave his name.
Bill is rarely late for work.
Bob helped a child.
Tom shared his lunch with a co-worker.
Scott cheated on an exam.
Alan planted seedlings in a park.
Henry went out of his way to return a lost wallet to the owner.
Nathan took neighborhood kids swimming.
John is considered a very dependable coworker.
Chad always talks about himself and his problems.
Josh finished his homework on time.
Lane is well-like by his colleagues.
Davis read a story to his daughter.
Ron made prank phone calls to his teacher.
Bruce never returns library books on time.
Ken helped a lost child in a supermarket.
David converses easily with people he doesn t know well.
Fred gave blood to the Red Cross.
Alex kicked a dog.
Devin donated his clothes to charity.
Mark learned how to fly an airplane.
Gary earned an A on his research paper.
Ted ran a red light.
Jeff volunteered to tutor needy students.
Richard yelled at a boy who bumped into him.
Eric drove his elderly neighbor to the grocery store.
Vincent forgot about his job interview.
Keith organized a birthday party for a friend.
Colin works out to keep himself in good shape.
Robert talks with food in his mouth.
Scott received a promotion at work.
Norman often tailgates when he is driving
Eliot sings in the church choir.
William rarely washes his car.
Pete is recognized as an excellent musician.
Don took a hurt stray dog to the vet.
Roger repaired his neighbor s lawnmower.
Craig helped a friend move.
Done!
Group Ratings Your next task is to rate each of the groups. Use the scale below: 1: Strongly Disagree 7: Strongly Agree You should use intermediate values as well as these two extremes. How would you characterize group A? Group B?
Debriefing Group A (n = 26 members) 18 positive statements 8 negative statements 9:4 ratio of positive to negative statements Group B (n = 13 members) 9 positive statements 4 negative statements 9:4 ratio of positive to negative statements
Debriefing The ratio of positive and negative events was exactly the same for Group A and Group B! Did we rate the Groups the way we should have? Are our ratings of the Groups exactly equal?
Illusory Correlation This demonstration illustrates an Illusory Correlation the perception of a relationship where none exists, or perception of a stronger relationship than actually exists. Another way to think of it a false impression that two variables correlate.
Illusory Correlation The joint occurrence of two distinctive events (minority member Group B & distinctive event - negative behavior) probably attracted more attention and caused faulty impressions.
Examples: Illusory Correlation You believe that people in urban environments tend to be rude. Therefore, when you meet someone who is rude you assume that the person lives in a city. A woman believes that pit bulls are inherently dangerous. When she hears of a dog attack in the news, she assumes it is a pit bull that attacked. A student does well on a test when he uses his blue pencil. For all future tests he uses only his blue pencil. You catch a lot of fish off of one dock, you feel that there are more fish there than anywhere else on the lake.
Illusory Correlation How could Illusory correlation be one reason individuals become prejudiced? Research has shown that White Americans overestimate the arrest rate of African Americans (Hamilton & Sherman, 1996). African Americans = minority Arrest Rate = distinctive event
What is going on in this picture? We cannot say exactly, but we can describe what we see. Thus we have.. Descriptive Research a systematic, objective observation of people. Any research that observes and records. Does not talk about relationships, it just seeks to describe thoughts, behaviors, and attributes.
Research goal and strategy: description Descriptive research is a systematic, objective observation of people. The goal is to provide a clear, accurate picture of people s behaviors, thoughts, and attributes. Strategies for gathering this information: Case Study: observing and gathering information to compile an in-depth study of one individual Naturalistic Observation: gathering data about behavior; watching but not intervening Surveys and Interviews: having other people report on their own attitudes and behavior
Case Study Examining one individual or group in depth Benefit: can be a source of ideas about human nature in general. Example: cases of brain damage have suggested the function of different parts of the brain (e.g. Clive Wearing) Danger: overgeneralization from one example; the Kardashians are a family from the United States, so I guess that is what it is like in the US!