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Part 2: Research Methods
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Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Dec 30, 2015

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Page 1: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Part 2:Research Methods

Page 2: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Why is psychological research important?

• Psychologists do more than just wonder about human behavior

• Psychological research has an enormous impact on all facets of our lives– how parents choose to discipline their children – how companies package and advertise their products– how governments choose to punish or rehabilitate

criminals• Understanding how psychologists do research is vital to

understanding psychology itself.

Page 3: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Scientific MethodQuestion/Observation

Hypothesis

Test Hypothesis

Results

Conclusions

Theory

Additional hypothesis Reject and revise

hypothesis

Other psychologist replicateand test their theories

Page 4: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Research Methods

Page 5: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Experimental Method

HypothesisDependent variable

Independent variableControl group

Experimental group

Page 6: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Extraneous Variables in Experiments

• Variables other than the independent variable that could affect the dependent variable are called extraneous variables. – Example: An educational psychologist has developed a new learning

strategy and is interested in examining the effectiveness of this strategy. The experimenter randomly assigns students to two groups. All of the students study text materials on a biology topic for thirty minutes. One group uses the new strategy and the other uses a strategy of their choice. Then all students complete a test over the materials.

Page 7: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Dealing With Extraneous Variables

• Random Assignment – participants have an equal chance of being placed in each group.

Page 8: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Advantages of Experimental Method

• Can show cause-and-effect relationships between variables

Page 9: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Disadvantage of Experimental Method

• Can not be generalized to the real world because an artificial situation.

• Cant be used to study everything– Cant control variables – Unethical

Page 10: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Bias in Research

• Bias is the distortion of results by a variable. – Sampling bias occurs when the sample studied in an experiment

does not correctly represent the population the researcher wants to draw conclusions about.

– Subject bias - Research subjects’ expectations can affect and change the subjects’ behavior, resulting in subject bias. Such a bias can manifest itself in two ways:

• Placebo effect • Social desirability bias

– Experimenter bias occurs when researchers’ preference or expectations influence the outcome of their research. Researchers see what they want to see.

• Double-blind experiment

Page 11: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Correlations • Used to describe how two sets of data relate to each

other – Ex: students grades and number of hours slept

• Correlation coefficient measures the strength of the relationship between two variables. – Always a number between –1 and +1. – The sign (+ or –) of a correlation coefficient indicates the

nature of the relationship between the variables.

Page 12: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

• A positive correlation (+) means that the variables move in the same direction.

• Example: The more years of education a person receives, the higher his or her yearly income is.

Page 13: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

• A negative correlation (–) means that when one variable increases, the other one decreases.

• Example: The more hours a high school student works during the week, the fewer A’s he or she gets in class.

Page 14: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

• No correlation – variables do not relate

Page 15: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

• The higher the correlation coefficient, the stronger the correlation. – A +0.9 or a –0.9 indicates a very strong correlation – A +0.1 or a –0.1 indicates a very weak correlation. – A correlation of 0 means that no relationship exists

between two variables.

Page 16: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.
Page 17: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

• correlation is not the same as causation. Two factors may be related without one causing the other to occur. Often, a third factor explains the correlation.– A psychologist uses the survey method to study the

relationship between balding and length of marriage. He finds that length of marriage correlates with baldness. However, he can’t infer from this that being bald causes people to stay married longer. Instead, a third factor explains the correlation: both balding and long marriages are associated with old age.

Page 18: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

APA Ethical Guidelines for Research

• In the past, researchers performed all kinds of questionable experiments in the name of science.

• Now psychologist must submit their research proposals to the Institutional Review Board (IRB)- Procedural errors - Ethical Violations

*For humans and animals*

Page 19: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Human Research

1. Informed Consent – participants must know that they are involved in research and give their consent or permission

Page 20: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

2. Deception – if the participants are deceived in any way about the nature of the study, the deception must not be so extreme as to invalidate the informed consent. Also, researchers must be very careful about the trauma deception may cause.

Page 21: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

3. Coercion – participants cannot be coerced in any way to give consent to be in the study.

Page 22: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

4. Anonymity – the identities and actions of participants must not be revealed in any way by the researcher.

Page 23: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

5. Risk – participants cannot be placed at significant mental or physical risk. This clause requires interpretation by the review board.

Page 24: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

6. Debriefing procedures –participants must be told of the purpose of the study and provided with ways to contact the researchers about the results.

Page 25: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Milgram Experiment

Milgram Experiment Original Video http://www.youtube.com/watch?v=W147ybOdgpE

Milgram Experiment Video 2 http://www.youtube.com/watch?v=HwqNP9HRy7Y

Page 27: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Animal Research

1. Purpose- research must have a clear scientific purpose.

2. Care – animals must be cared for and housed in humane way.

3. Acquiring animals – animals must be aquired legally.

4. Suffering – experimental procedures must employ the least amount of suffering feasible.

5. Supervision – trained psychologist must supervise all animal research.

Page 28: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

#1 David Reimer1965 – 2004

Page 29: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

#2 The Well of Despair 1960

Page 30: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

#3 Milgram Study1974

Page 31: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

#4 Learned Helplessness1965

Page 32: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

#5 Little Albert1920

Page 33: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

#6 Landis’ Facial Expressions Experiment

1924

Page 34: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

#7 Monkey Drug Trials1969

Page 35: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

#8 Stanford Prison Experiment1971

Page 36: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

#9 The Aversion Project 1970s and 1980s

Page 37: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

#10 The Monster Study1939

Page 38: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Qualitative Data

• Deals with descriptions • Data can be observed

but not measures

Page 39: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Quantitative Data

• Deals with numbers • Data can be measured

Page 40: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

– Frequency Distribution • Frequency distribution table • Histogram• Frequency polygon

Descriptive Statistics

Page 41: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

LETS TRY IT!

• Fifteen people were asked to state the number of hours they exercise in a seven day period. The results of the survey are listed below. Make a frequency table and histogram to display the data.

8, 2, 4, 7.5, 10, 11, 5, 6, 8, 12, 11, 9, 6.5, 10.5, 13

Page 42: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Frequency Distribution Table

Hours of Exercise Tally Frequency

0 – 2 I 1

3 – 5 I I 2

6 – 8 I I I I I 5

9 – 11 I I I I I 5

12 – 14 I I 2

Page 43: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.
Page 44: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

More Descriptive Statistics

• Central Tendency– Mode – Median – Mean

• Variance– Range – Standard deviation

• Correlation coefficients

$25,000-Pam $25,000- Kevin$25,000- Angela$100,000- Andy$100,000- Dwight$200,000- Jim$300,000- Michael

Page 45: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Closer Look at Standard Deviation

• Standard Deviation: The Standard Deviation is a measure of how spread out the numbers are.

• The higher the variance or SD, the more spread out the distribution is.

• Do scientists want a big or small SD?

Example: There was a, now discredited, theory proposed that claimed in IQ tests Men and Women had the same average IQs but men had a larger standard deviation than women. That is that there were more male geniuses and mentally challenged people than women. While woman's IQs tended to sit more around the average.

Page 46: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Why is Standard Deviation Important?

• using the Standard Deviation we have a "standard" way of knowing what is normal, and what is not.

Page 47: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

How to Calculate Standard Deviation of a Sample

Page 48: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Inferential Statistics

- Measures of Statistical Significance - Probability results are due to chance less than 5%

to be statistically significant

Page 49: Part 2: Research Methods. Why is psychological research important? Psychologists do more than just wonder about human behavior Psychological research.

Lets Try It!

• Suppose we want to test the effectiveness of a medicine to reduce the likelihood of a heart attack. We design a controlled study of two groups of people. Group A takes the medicine, and Group B takes a placebo.

• Suppose that Group A has a much lower rate of heart attacks than Group B. Is this due to chance, or the medicine?– Suppose the p-value for the study is .04. – Suppose the p-value had been .1.