1. Psychological Research Methods- Unit 2
Excavating Human Behaviors

2. Hindsight Bias
Monday Morning Quarterbacking!!!
The tendency to believe, after learning the outcome, that you knew it all along.
After the Chris Brown/Rihanna incident….people said they knew Chris Brown was a violent kid!!! Did they really?

3. Overconfidence We tend to think we know more than we do.
82% of U.S. drivers consider themselves to be in the top 30% of their group in terms of safety.
81% of new business owners felt they had an excellent chance of their businesses succeeding. When asked about the success of their peers, the answer was only 39%. (Now that's overconfidence!!!)

4. Components of a Scientific attitude
Humility- vulnerability
Curiosity
Skepticism- question authority
Use empiricism- Experience and observation
Scientific attitude asks 2 questions: What and How

5. First have a theory
An explanation using an integrated set of principles that organizes observations and predicts behavior or events.
Example: If we notice that depressed people talk about their lives in a negative way we can theorize that at the heart of depression is low esteem. Now we must test this So we develop a hypothesis

6. Hypothesis Have operational definitions.
A tentative theory that has not yet been tested. A statement of fact: The length of one’s hair determines IQ
Have operational definitions.
Allow studies to be replicated

7. Operational Definitions
Explain what you mean in your hypothesis.
How will the variables be measured in “real life” terms.
How you operationalize the variables will tell us if the study is valid and reliable.
Let’s say your hypothesis is that chocolate causes violent behavior.
What do you mean by chocolate?
What do you mean by violent behavior?

8. Types of Research
Descriptive
Correlational
Experimental

9. Descriptive Research Any research that observes and records.
What is going on in this picture?
We cannot say exactly, but we can describe what we see.
Thus we have…..
Descriptive Research
Any research that observes and records.
Does not talk about relationships, it just describes.

10. Types of Descriptive Research
The Case Study
The Survey
Naturalistic Observation

11. The Case Study
Where one person (or situation) is studied in depth a detailed study. Usually done by questioning those who know you , teachers, family, friends

12. The Survey Method
Used in both descriptional and correlational research.
Use Interview, mail, phone, internet etc…
The Good- cheap, anonymous, diverse population, and easy to get random sampling (a sampling that represents your population you want to study).

13. Why do we sample?
One reason is the False Consensus Effect: the tendency to overestimate the extent to which others share our beliefs and behaviors.

14. Survey Method: The Bad Low Response Rate
People Lie or just misinterpret themselves.
Wording Effects
How accurate would a survey be about the frequency of diarrhea?

15. Naturalistic Observation
Observing and recording behavior in natural environment.
No control- just an observer.

16. Correlational Research
Detects relationships between variables.
Does NOT say that one variable causes another. Correlation is not causation
There is a positive correlation between ice cream and murder rates. Does that mean that ice cream causes murder?

17. Measured using a correlation coefficient.
A statistical measure of the extent to which two factors relate to one another
Positive correlations are Direct Correlations
Negative Correlations known as Inverse Correlations

18. How to Read a Correlation Coefficient

19. Correlation Coefficient
A number that measures the strength of a relationship.
Range is from -1 to +1
The relationship gets weaker the closer you get to zero.
Which is a stronger correlation?
-.13 or +.38
-.72 or +.59
-.91 or +.04

21. Correlation X is the independent variable- what is manipulated
Y is the dependent variable- what is measured

22. The weight of a car and miles per gallon: cars that are heavier tend to get less miles per gallon of gas.
School achievement and days absent from school: people who miss more days of school tend to have lower GPAs.
Vaccinations and illness: The more that people are vaccinated for a specific illness, the less that illness occurs.

23. What is the correlation? Hypothesis?

24. What is the correlation
The more young children watch TV, the less they read
The more sexual content teens see on TV, the more likely they are to have sex
The more often adolescents eat breakfast, the lower the body fat
The larger your shoe size the smarter you are

25. Correlation does not mean causation
Correlations help to predict
Low self esteem may be a predictor of depression but does it cause depression
Correlations indicates the possibility but it DOES NOT PROVE CAUSATION

26. Illusory Correlations
A perceived but nonexistent correlation
Random coincidences
Often caused by confirmation bias- look for evidence that supports our belief- ignore evidence that does not support out beliefs
Every time I wash my hair it rains. Washing my hair must cause it to rain.

27. Experimental Research
Explores cause and effect relationships.
Aggression
Eating too many bananas causes

28. Steps in Designing an Experiment
Hypothesis
Pick Population: Random Sampling everyone has the same chance of being selected Used in surveys, interviews and experiments
Random Assignment- assigning to the control or experimental groups. ONLY used in experiments
Operationalize the Variables
Identify Independent and Dependent Variables.
Look for Extraneous ( confounding) Variables
Type of Experiment: Blind, Double Blind etc..
Gather Data
Analyze Results

29. Experimental Vocabulary
Independent Variable: factor that is manipulated
Dependent Variable: factor that is measured
Extraneous Variables (Confounding Variables): factors that affect DV, that are not IV.
Experimental Group: Group exposed to IV
Control Group: Group not exposed to IV (no change in behavior)

30. Beware of Confounding Variables
The object of an experiment is to prove that A causes B.
A confounding variable is anything that could cause change in B, that is not A.
If I wanted to prove that smoking causes heart issues, what are some confounding variables?
Lifestyle and family history may also effect the heart.

31. Experimenter Bias Another confounding variable. Not a conscious act.
Double-Blind Procedure.

32. Hawthorne Effect But even the control group may experience changes.
Just the fact that you know you are in an experiment can cause change.
Whether the lights were brighter or dimmer, production went up in the Hawthorne electric plant.

33. Other Important Stuff
Random assignment ( control or experimental groups) holds constant all the factors that can affect an experiment
The more controlled the environment the more likely you will be able to tell whether the IV caused the DV
Be aware of the Placebo affect – belief that a treatment works because a trusted person told them it would work

34. Placebo Effect

35. Use of statistics
Used in descriptive, correlational and experimental research
Helps us interpret what we may miss with just our eyes

36. Figure 2.8 Read the scale labels An American truck manufacturer offered graph (a)—with actual brand names included—to suggest the much greater durability of its trucks. Note, however, how the apparent difference shrinks as the vertical scale changes in graph (b).
© 2011 by Worth Publishers

37. Analyze Results/ Describing Data
Use measures of central tendency (mean, median and mode). organize data in a meaningful way very often a bar graph
Use measures of variation (range and standard deviation). SD answers how much scores vary around the mean. Range gap between the highest and lowest scores

38. Mean, Median, Mode Mean= Average 46 + 20 + 10 = 76
Mean = 25.3 Most Common, Can distort or skew scores
Median= the midpoint 50th percentile
1,2,3,4,5,
Median =3
Mode= frequently occurring score
1,2,2,3,3,3,4
Mode = 3
Simplest

39. Central Tendency Mean, Median and Mode.
Watch out for extreme scores or outliers.
Let’s look at the salaries of the employees at Dunder Mifflen Paper in Scranton:
$25,000-Pam
$25,000- Kevin
$25,000- Angela
$100,000- Andy
$100,000- Dwight
$200,000- Jim
$300,000- Michael
The median salary looks good at $100,000.
The mean salary also looks good at about $110,000.
But the mode salary is only $25,000.
Maybe not the best place to work.
Then again living in Scranton is kind of cheap.

40. A Skewed Distribution
Are the results positively or negatively skewed?

41. Distributions Outliers skew distributions.
If a group has one high score, the curve has a positive skew (contains more low scores). Pulls the mean toward the higher end
If a group has a low outlier, the curve has a negative skew (contains more high scores)Pulls mean toward the lower end

42. Measures of variation
Helps to know the amount of variation- how similar or diverse the scores are
Range provides a rough estimate of variation. Range from the lowest to highest
Standard deviation is better – how much the scores deviate from one to another and how scores vary around the mean

43. Normal Distribution
In a normal distribution, the mean, median and mode are all the same.
Range= the gap between the highest and lowest scores

44. Figure 2.10 The normal curve Scores on aptitude tests tend to form a normal, or bell-shaped, curve. For example, the Wechsler Adult Intelligence Scale calls the average score 100.
© 2011 by Worth Publishers

45. Scores A unit that measures the distance of one score from the mean.
A positive z score means a number above the mean.
A negative z score means a number below the mean.

46. When is a Difference Significant?
Statistical tests help us determine whether differences are meaningful
Remember: Statistical significance indicates the likelihood that a result will happen by chance.
Goal is to get a significance level of 5% means that 5% of the results was due to chance and 95% due to your independent variable- Valid study
EX: test with a SD of 5 means all who took the test scored similarly; a SD of 50 means the test takers scores were not at all similar

48. Other types of studies
Longitudinal- Study one group over a period of years
Cross- sectional- studies the same interest with different population groups of different ages: example How one deals with stress. Study 5, 10, 15, 20, 25 etc. year olds

49. APA Ethical Guidelines for Research
IRB- Internal Review Board
Both for humans and animals.

50. Human Research No Coercion- must be voluntary Informed consent
Confidentiality
No significant risk
Must debrief

52. Animal Research Clear purpose Treated in a humane way
Acquire animals legally
Least amount of suffering possible.