Unit 2Psychological Research

Methods

Why do we have to learn this stuff?

Psychology is first and foremost a science.

Thus it is based in research.

Types of Research

•Descriptive

•Correlational

•Experimental

Descriptive Research• Any research that observes and records.

• Does not talk about relationships, it just describes.

What is going on in this picture?

We cannot say exactly, but we can describe what we see.

Thus we have…..

Types of Descriptive Research

• The Case Study

• The Survey

• Naturalistic Observation

The Case Study• Where one person (or situation) is observed in

depth.

What are the strengths and weaknesses of using a tragedy like the Columbine School Shootings as a case study?

Naturalistic Observation

• Observing and recording behavior in natural environment.

• No control- just an observer.

What are the benefits and detriments of Naturalistic Observation?

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).

Random Sampling

Why do we sample?

• Reduced cost: It is obviously less costly to obtain data for a selected subset of a population, rather than the entire population. Furthermore, data collected through a carefully selected sample are highly accurate measures of the larger population. Public opinion researchers can usually draw accurate inferences for the entire population of the United States from interviews of only 1,000 people.

• Speed: Observations are easier to collect and summarize with a sample than with a complete count. This consideration may be vital if the speed of the analysis is important, such as through exit polls in elections.

• Greater scope: Sometimes highly trained personnel or specialized equipment limited in availability must be used to obtain the data. A complete census (enumeration) is not practical or possible. Thus, surveys that rely on sampling have greater flexibility regarding the type of information that can be obtained.

Survey Method: The Bad

• Low Response Rate

• People Lie or just misrepresent themselves.

•Wording Effects

How accurate would a survey be about the frequency of drug use?

Correlational Research• Detects relationships between variables.

• Does NOT say that one variable causes another. CORRELATION NOT CAUSATION

There is a positive correlation between ice cream and murder rates. Does that mean that ice cream causes murder?

Measured using a correlation coefficient.

• A statistical measure of the extent to which two factors relate to one another

How to Read a Correlation Coefficient

Experimental Research

• Explores cause and effect relationships.

arousal decreases test performance

Experimental Vocabulary

Hypothesis

• Your hypothesis is an educated guess/prediction about the effect of particular events/treatments/factors

• Your hypothesis may be general (e.g., this course will change comprehension abilities),

• or specific (e.g., this course will improve comprehension abilities by at least 10%).

Independent Variable

• Whatever is being manipulated in the experiment.

• Hopefully the independent variable brings about change.

In an experiment looking at the effects of studying on test scores, studying would be the independent variable.

Dependent Variable

• Whatever is being measured in the experiment.

• It is dependent on the independent variable.

In the research on studying and test scores, the test scores would be the dependent variable.

Watch the following video. As you are watching record how

many times you witness violent behavior.

• https://search.yahoo.com/yhs/search?p=tom+and+jerry+violent+episode&ei=UTF-8&hspart=mozilla&hsimp=yhs-002

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.

EX: The experimenter wants to determine how recreational drugs affect a person's sense of humor.

Beware ofConfounding Variables

Ex: If I wanted to prove that smoking causes heart issues, what are some 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.

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.

Experimenter Bias

• Another confounding variable.

• Not a conscious act.

• Double-Blind Procedure.

Random Assignment

• Once you have a random sample, randomly assigning them into two groups helps control for confounding variables.

• Experimental Group v. Control Group.

• Frequency Distribution

• Frequency distribution table

• Histogram

• Frequency polygon

Descriptive Statistics

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.

2, 4, 5, 6, 6, 7, 8, 8, 9, 10, 10, 11, 11, 12, 13

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

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

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.

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.

Why is Standard Deviation Important?

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

How to Calculate Standard Deviation of a

Sample

Inferential Statistics

- Measures of Statistical Significance (P-value)

- Probability results are due to chance less than 5% to be statistically significant

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.

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*

Human Research

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

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.

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

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

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

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

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.

#1 David Reimer1965 – 2004

#2 The Well of Despair 1960

#3 Milgram Study1974

#4 Learned Helplessness1965

#5 Little Albert1920

#6 Landis’ Facial Expressions Experiment

1924

#7 Monkey Drug Trials1969

#8 Stanford Prison Experiment

1971

#9 The Aversion Project 1970s and 1980s

#10 The Monster Study1939