1. Research Methods
AP Psychology-Unit 2

2. AP EXAM-INTRO TO RESEARCH How do psychologists ask & answer questions?
Research Methods (8–10%)
AP students in psychology should be able to do the following:
• Differentiate types of research (e.g., experiments, correlation studies, survey research, naturalistic observations, case studies) with regard to purpose, strengths, and weaknesses.
• Describe how research design drives the reasonable conclusions that can be drawn (e.g., experiments are useful for determining cause and effect; the use of experimental controls reduces alternative explanations).

3. PSYCHOLOGY’S MAIN GOAL
Psychology is a scientific study because it:
Uses empirical data to test hypotheses
Describes, predicts, and explains behavior and mental processes
Is the systematic collection of observation data
The goal of psychology is to develop explanations for behavior and mental processes…explain why we do what we do.
These explanations, based on solid empirical studies are called theories.
A theory is a testable explanation for a set of facts or observations.
Empirical: based on testing or experience
Remember back to unit 1: early behaviorists had a problem with psychology including anything that wasn’t OBSERVABLE, e.g. the mind

4. THE SCIENTIFIC METHOD

5. HYPOTHESIS
Idea or explanation that must be tested through study and experimentation
Must be replicable
Aims to explain a phenomenon not “prove” hypothesis; can only support or disprove
Has operational definitions: describes exactly what the variables are and how they are measured within the context of your study
E.g. If you were doing a study on the impact of sleep deprivation on driving performance, you would need to operationally define what you mean by sleep deprivation and driving performance.
Show theory vs. hypothesis rap

6. How might we operationally define the following?
The teacher wants to find a way to help Billy act more friendly toward the other children.
A psychologist wants to know if his new form of psychotherapy will make people feel less depressed.
College athletes are not as smart as regular students.
Overall, senior Mustangs are nicer than junior Mustangs.
School spirit is at an all-time low.

7. TYPES OF RESEARCH
1. Descriptive
2. Correlational
3. Experimental

8. DESCRIPTIVE RESEARCH Any research that observes and records
Does not talk about relationships, merely describes
Also called “statistical research”
case study
the survey
naturalistic observation

9. DESCRIPTIVE RESEARCH: CASE STUDY
Case study: approach used to obtain an in-depth analysis of a person, group, or phenomenon
Analysis of nearly every aspect of subject’s life and history
Clinical psychologists
Limitations
Ex. Case study—Kitty Genovese
Analysis=to identify patterns and causes for behavior
Share link to article on Kitty Genovese case

10. DESCRIPTIVE RESEARCH: SURVEY METHOD
Determines self-reported attitudes, opinions, or behaviors of people usually by questioning a representative, random sample of people
Given when you want to know how people “feel”
Considered descriptive and correlational
Interview
Mail
Phone, etc.
Advantages: cheap, anonymous, can get diverse population, easy to get random sampling

11. DESCRIPTIVE RESEARCH: SURVEY METHOD
Validity of data
Questions
Subjects
Limitations
Can still be a beneficial way to gather data & look at raw numbers
Students often confuse the use of surveys to measure the dependent variable in an experiment with the survey method.
Need a representative sample or a random sample (also called random selections)
Willingness of people to participate; people may answer the way they THINK they should answer rather than being truthful
Answers can depend on how questions are asked and how respondents are selected
Sampling bias

12. Why do we sample?
False Consensus Effect: tendency to overestimate the extent to which our opinions, habits, beliefs, values and behaviors are “normal” and shared by others

13. DESCRIPTIVE RESEARCH: NATURALISTIC OBSERVATION
Naturalistic observation: observing and recording behavior in natural environment
No control or interaction—JUST observation
Not to be confused with field experiments
Goal=get realistic picture of participants’ behavior
Ex. of naturalistic observation-Jane Goodall

14. DESCRIPTIVE RESEARCH: NATURALISTIC OBSERVATION
Drawbacks
Hawthorne Effect: merely selecting individuals to participate can impact their behavior and performance alone

15. EXPERIMENTAL RESEARCH
Explores cause and effect relationships
Only research method that isolates cause and effect
Famous experiments in psych:
Pavlov’s dogs
Milgram’s obedience study
Asch’s conformity experiment
Psychology study leaves Aussies in shock video?

16. EXPERIMENTAL RESEARCH
Independent variable (IV): factor that is manipulated
Dependent variable (DV): factor that is measured
Extraneous variables: factors that affect DV that are not IV
Experimental group: group exposed to IV
Control group: group not exposed to IV
Placebo: inert substance that is in place of IV in control group
Independent variable influences change in the dependent variable

17. KEY TERMINOLOGY
Valid = research measures what the researcher set out to measure; it is accurate
Reliable = research can be replicated; it is consistent
Sample = group of participants
Stratified sampling = a process that allows a researcher to ensure that the sample represents the population on some criteria (e.g., representation of different races, genders, etc.)
Participant-relevant confounding variable = using random assignment limits the effect
Situation-relevant confounding variable = situations into which the different groups are put must be equivalent except for differences produced by the IV

18. EXPERIMENTAL METHOD
Experimenter bias
Single-blind
Double-blind

19. CAFFEINE EXPERIMENT
On printed notes

20. CORRELATIONAL STUDIES
A correlation study is one where researchers try to show the relationship or correlation between two variables (coincidence).
Correlation studies are largely based in statistics.
It is important to remember that correlation does not necessarily mean causation.
If there is no association between two variables, then there is no causal connection.
Correlation does not equal causation EX. People who carry lighters are likely to get cancer…

21. TYPES OF CORRELATION
Positive correlation: the variables go in the SAME direction
Negative correlation: the variables go in DIFFERENT directions

22. SCIENCE VS. COMMON SENSE
Overconfidence is common. 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 business succeeding. When asked about the success of their peers, the answer was only 39%.
“They couldn’t hit an elephant at this distance.”
–General John Sedgwick just before being killed
during a U.S. Civil War battle, 1864

23. SCIENCE VS. COMMON SENSE
Hindsight bias: the tendency to believe, after learning the outcome, that you knew it all along

24. STATISTICS

25. AP EXAM: RESEARCH METHODS (8-10%)
Distinguish the difference between the purposes of descriptive and inferential statistics.
Discuss the value of reliance on operational definitions and measurements in behavioral research.
Statistical procedures analyze and interpret data and let us see what the unaided eye is missing.

26. CORRELATION: NEGATIVE AND POSITIVE
Correlation: A relationship between two variables in which change in one variable is reflected in the changes in the other variable.
Correlation Coefficient:
A number between –1 and +1 expressing the degree of relationship between two variables.
Shows the strength of the relationship
The relationship gets weaker the closer you get to zero.

27. CORRELATION COEFFICIENT
A statistical measure of the extent to which two factors relate to one another
Is statistical measure; helps us figure out how closely two things vary together and thus how well one predicts the other EX knowing how much aptitude test scores correlate with school success tells us how well the scores predict school success

28. COMPARING CORRELATION COEFFICIENTS
If the correlation coefficient is a positive number, there is a positive correlation (connection) between the variables.
SAT scores and college achievement—among college students, those with higher SAT scores also have higher grades
If the correlation coefficient is a negative number, there is a negative correlation (connection) between variables.
Education and years in jail—people who have more years of education tend to have fewer years in jail
If the correlation coefficient is 0, there is no correlation between variables.
Saying correlation is negative says nothing about its strength or weakness; correlation = negative if two sets of scores relate inversely; EXAM TIP in psych pos/neg does NOT mean good/bad
Positive Correlation
Negative Correlation
No Correlation

29. CORRELATION: POSITIVE OR NEGATIVE?
1. The more children and youth used various media, the less happy they were with their lives.
2. The longer children were breast-fed, the greater their later academic achievement.
3. The more income rose among a sample of poor families, the fewer psychiatric symptoms their children experienced.
ANSWERS: 1. negative; 2. positive; 3. negative

30. QUANTITATIVE DESCRIPTIVE STATISTICS
When dealing with quantitative data, researchers often compute descriptive statistics that can summarize important characteristics of the data numerically.
There are two basic classes of quantitative statistics: measures of central tendency and measures of variability or dispersion.

31. USING DATA: RESULTS & STATISTICS
Descriptive data
Numerical data used to measure and describe characteristics of groups; includes measures of central tendency (mean, median, mode) and measures of variation (range, standard deviation)
Central tendency: single score that represents a whole set of scores
Central tendency-tells us how much people generally scored

32. MEASURES OF CENTRAL TENDENCY
Mean (average): The measure of central tendency most often used to describe a set of data.
To calculate mean, simply add all the scores and divide by the number of scores.
While the mean is easy to calculate, it has a big downside. It can easily be influenced by extreme scores.
Median: A measure of central tendency represented by the score that separates the upper half of the scores in a distribution from the lower half.
The big advantage of this is the median is not effected by extreme scores.
Mode: A measure of central tendency which represents the score that occurs most often.

33. MEASURES OF CENTRAL TENDENCY
The weekly salaries of six employees at McDonalds are $140, $220, $90, $180, $140, $200.
For these six salaries, find:
(a) the mean
(b) the median
(c) the mode

34. MEASURES OF CENTRAL TENDENCY
Answers
Mean: =$ 6
Median: 90,140,140,180,200,220
The two numbers that fall in the middle need to be averaged.
= $160 2
Mode: 90,140,140,180,200,220
The number that appears the most is $140

35. USING DATA: RESULTS & STATISTICS
Variation: tells us how diverse data are
May be used to organize data meaningfully
Frequency distribution
Histograms
Range
Standard deviation
Range: distance between highest and lowest score
Standard deviation: index of variability that reflects how widely distributed or clustered around the mean the scores tend to be; s.d. is found by calculating how far each score in the data set is from the mean

36. FREQUENCY DISTRIBUTION
Frequency Distribution: A summary chart which shows how frequently each of the various scores in a set of data occur. For example, let’s suppose that you are collecting data on how many hours of sleep college students get each night. After conducting a survey of 26 of your classmates, you are left with the following set of scores: 7, 5, 8, 9, 4, 7, 9, 9, 6, 5, 6, 5, 9, 8, 6, 9, 7, 9, 8, 4, 7, 8, 7, 6, 4, 8 In order to make sense of this information, you need to find a way to organize the data. A frequency distribution is commonly used to categorize information so that it can be interpreted quickly in a visual way.

37. FREQUENCY DISTRIBUTION
In our previous example, the number of hours each week serves as the categories and the occurrences of each number are then tallied. Frequency distributions are often displayed in a table format
HOURS OF SLEEP EACH NIGHT
FREQUENCY 4 3 5 6 7 8 9
TOTAL 26

38. GROUPED FREQUENCY DISTRIBUTION
For data sets with a large range of scores from high to low, a researcher can create a grouped frequency distribution.
To be effective, the classes of scores must be mutually exclusive or nonoverlapping, and of uniform width.

39. HISTOGRAM A histogram is very similar to a bar graph
Depicts a frequency distribution where the height of the bars indicates the frequency of a group of scores.
Difference between a bar graph & a histogram I
Histogram = no spaces between bars
Bar Graph= Spaces between each bar

40. STANDARD DEVIATION
Standard Deviation (SD): A measure of variability that indicates the average distance between the scores and their mean.
A low standard deviation indicates that the data points tend to be very close to the mean, whereas high standard deviation indicates that the data are spread out over a large range of values.
Range: difference between the largest and smallest values and is a crude estimate of variation VIDEO?

41. NORMAL DISTRIBUTION
The standard deviation and mean together tell us a lot about the distribution of scores.
MEAN=50
SD=20
A data set with a mean of 50 (shown in blue) and a standard deviation of 20.

42. A standard deviation of 15 accounts for about 68% of responses.
NORMAL DISTRIBUTION
A normal distribution is a bell shaped curve.
A standard deviation of 15 accounts for about 68% of responses.

43. SKEWED DISTRIBUTION
A distribution is skewed if one of its tails is longer than the other.
The first distribution shown has a positive skew. This means that it has a long tail in the positive direction.
The second distribution has a negative skew since it has a long tail in the negative direction.
Finally, the third distribution is symmetric and has no skew (normal distribution).

44. REMEMBER… Outliers skew distributions.
If group has one high score, the curve has a positive skew (contains more low scores)
If a group has a low outlier, the curve has a negative skew (contains more high scores)

45. SCATTERPLOT
*a graphed cluster of dots, each of which represents the values of two variables
*the slope of the points suggests the direction of the relationship
*the amount of scatter suggests the strength of the correlation
little scatter indicates high correlation
*also called a scattergram or scatter diagram

46. INFERENTIAL STATISTICS
Numerical data that allow one to generalize—to infer from sample data the probability of something being true of a population
When sample averages are reliable, and when the difference between them is relatively large, we say the difference has statistical significance.
When is an observed difference reliable?
1. Representative samples are better than biased samples.
2. Less-variable observations are more reliable than those that are more variable.
3. More cases are better than fewer.
EX. Drug testing—if the meds worked for the sample, we estimate they will have the same effect on the rest of the population
Best basis for generalizing = NOT exceptional/memorable cases at extremes
Basketball—game-to-game points are consistent would be less variable and more reliable
Visiting more classes/universities as opposed to fewer

47. INFERENTIAL STATISTICS
Inferential statistics--based on probability
Conclusions are based on probabilities
Test the null hypothesis
Alternative hypothesis (aka research hypothesis or experimental hypothesis
Researchers hope to reject the null hypothesis and indirectly support the alternative hypothesis.
Inferential statistics are based on probability. They do not tell the researcher if a hypothesis is absolutely true or false.
They allow the researcher to make conclusions based on probabilities; and there is always a probability that the researcher has made the incorrect conclusion.
Do not test the experimental hypothesis directly; instead, they tests the null hypothesis, which generally states that the results are due to chance factors and that the IV had no effect on the DV
In addition to the null hypothesis, there is also an alternative hypothesis (sometimes call research hypothesis or experimental hypothesis) that says the results are not due to chance—that is, the results are hypothesized to be due to the IV

48. INFERENTIAL STATISTICS
If probability is very small that the obtained results were due to chance, then the researcher will reject the null hypothesis and say the results were not due to chance but must reflect systematic differences, presumably from the IV
In other words, a test of significance indicates the probability of the null hypothesis being true.
This is known as finding statistically significant results
Means the results are not due to chance, and if the experiment were repeated, similar results would likely be obtained

49. ETHICS

50. AP EXAM: RESEARCH METHODS (8-10%)
Identify how ethical issues inform and constrain research practices.
Describe how ethical and legal guidelines (e.g. those provided by the APA, federal regulations, local institutional review boards) protect research participants and promote sound ethical practice.

51. ETHICS
the principles of conduct governing an individual or a group 

52. GOAL OF PSYCHOLOGICAL RESEARCH
Applied research: solve practical problems
Basic research: explores questions that are of interest in psych, but may not generate immediate, real-world solutions
Applied: What is the best method for teaching someone to read?
Basic: Studying how people form their attitudes about others in different cultures in terms of intelligence

53. TUSKEGEE SYPHILIS EXPERIMENT
Voices of Civil Rights video

54. TUSKEGEE SYPHILIS EXPERIMENT
U.S. Public Health Service
Purpose: to study the “natural progression” of untreated syphilis in African-American men in Alabama
Study population
Participant compensation
Disclosure to participants
Population: 600 impoverished sharecroppers from Macon County, Alabama
Compensation: Participants were promised free health care, hot meals, and burial insurance
Disclosure: Were not told they were infected with the disease and were not treated with penicillin after it was proven to be an effective treatment

55. TUSKEGEE SYPHILIS EXPERIMENT
Ethical standards
Researchers knowingly failed to treat patients appropriately following 1940s validation of penicillin as effective antibiotic
Institutional Review Boards (IRB)
Led to federal laws/regulations requiring IRBs for the protection of human subjects in studies involving human subjects

56. APA ETHICAL GUIDELINES
Any type of academic research, must be proposed to ethics board: (IRB)
Board ultimately decides and gives researchers permission to carry out their research
Purpose of review process: assure, both in advance and by periodic review, that appropriate steps are taken to protect the rights & welfare of humans participating as subject in a research study
Goal of IRBs: protect human subjects from physical or psychological harm, which they attempt to do by reviewing research protocols and related materials

57. ETHICAL GUIDELINES-HUMAN RESEARCH
Ethical research involving human subjects must meet the following requirements:
1. no coercion
2. informed consent
3. deception
4. anonymity or confidentiality
5. risk
6. debriefing
Informed consent: must know they are involved in research
Deception: if deceived in any way about nature of the study, the deception must not be so extreme as to invalidate I.C. Must also be careful about possible trauma
Anonymity: identities and actions of individuals may not be revealed by researchers
Risk: participants cannot be placed at significant mental or physical risk; requires interpretation by IRB
Debriefing: must be told of purpose of the study and provided with ways to contact the researchers about the results
Sci show video with Hank Green

58. ETHICAL GUIDELINES-ANIMAL RESEARCH
Must have a clear scientific purpose
Research must answer a specific, important scientific question
Animals chosen must be best-suited to answer question at hand
Must care for the animals in a humane way
Must acquire animal subjects legally
Must design experimental procedures that employ the least amount of suffering feasible

59. ETHICS What is acceptable in experimentation and who decides?
Tony Lamadrid
_1_human-subject