Methods

Types of Research

TODAY’S OBJECTIVE

Explain basic methods of psychological research.

BASIC CONCEPTS Basis of scientific method

Making observations in systematic way

Follow strict rules of evidence

Critical thinking about evidence

IMPORTANT KEY TERMS

Variable: anything that can change

Theory: broad idea or set of closely related ideas that attempt to explain observations

Hypothesis: Educated guess derives logically from a theory

GOALS OF PSYCHOLOGICAL RESEARCH Description of social behavior

Ex: Are people who grow up in warm climates different from those in cold climates?

Establish a relationship between cause & effect Ex: Does heat cause higher amounts of aggression?

Develop theories about why people behave the way that they do Ex: We dislike Duke students to feel better about

ourselves Application

Creating effective therapeutic treatments, more successful negotiation tactics, and greater understanding amongst groups of people

EMPIRICAL RESEARCH Empirical

Knowledge based on direct observation

Publicly (confirmable) observable behavior

Theory

Set of ideas which try to explain what we observe

Goal is to find support OR disprove

We can never prove!!

Y SCIENTIFIC METHOD 1. OBSERVE SOME PHENOMENON /

SELECT A TOPIC

2. FORMULATE HYPOTHESIS AND PREDICTIONS

3. TESTING THROUGH EMPIRICAL RESEARCH

4. DRAWING CONCLUSIONS

5. EVALUATING THE THEORY

THE METHOD 1. Select a topic

Good theory: broad idea or set of closely related ideas that attempt to explain observations

Has predictive power

Is simple & straightforward

2. Formulate hypotheses

Hypothesis: specific statement of expectation derived from theory

State the relationship between two variables

Variable: can be any event, characteristic, condition, or behavior

TESTING 3. Has to be done through EMPIRICAL RESEARCH

*Knowledge based on

direct observation*

THE METHOD 4. Drawing conclusions

• Based on data analysis

• Data needs to be able to be REPLICATED for the theory to be proven or disproven.

5. Evaluating the Theory

• Never really ends

• Others will look at the theory and replicate and retest

TYPES OF RESEARCH

Commonly use 3 types of research:

1. Descriptive

2. Correlational

3. Experimental

DESCRIPTIVE RESEARCH Simplest method of scientific inquiry

About describing some phenomenon

Ex: defining what this thing is, how often does it occurs, etc.

By itself, cannot prove what causes the event but it can reveal important info

Types of Descriptive Research:

1. Observation

2. Surveys and Interviews

3. Case Studies

Descriptive Research Types 1. Observation: Have to do so without

disturbing what/who is being observed.

2. Surveys and Interviews: ask people what they think, their opinions, etc.

- Often the best and quickest way to gain information

3. Case Studies: in-depth look at a single individual

- Provides a dramatic, detailed look of a person’s lives

CORRELATIONAL RESEARCH Tells us about the relationship between two variables

Named for the statistical technique used to analyze the data

Degree of the relationship is expressed numerical value = coefficient (r)

The number expressed the strength of the relationship

Value of the coefficient always fall between +1.00 and -1.00

The closer the number is to +1.00, the stronger the relationship

The sign (+ or -) expresses the direction of the relationship

Positive (+) means that as one variable increases, the other also increases = Same direction

Negative (-) means that as one increases, the other decreases = Opposite direction

ZERO correlation means that there is no systematic relationship between the two variables

IMPORTANT TO REMEMBER CORRELATION DOES NOT EQUAL

CAUSATION!!

Correlation only means that two variables change together

Being able to predict one event based on the occurrence of another event does not necessarily tell us anything about the cause of either event!!

Remember: there are other factors that may have not been measured

EXPERIMENTAL RESEARCH Mostly done in highly controlled conditions

(LAB)

Experiment: carefully regulated procedure in which the researcher manipulates one or more variables that are believed to influence some other variables.

Variables: anything that can be changed

Independent Variable: manipulated experimental factor, affects the dependent var. (cause)

Dependent Variable: affected by the indep. var.

Usually what is being studied (effect)

What (i.d) is affecting what (d.)?

Confederate: Pseudo subject in a social exp.

EXAMPLE #1 A researcher wanted to study the effects of sleep

deprivation on physical coordination. The researcher selected 25 year-old male college students and deprived some of the subjects to either 24, 36, or 45 hours of sleep.

In the present study the independent variable was:

a) the length of time the subjects were deprived of sleep. b) the age of the subjects. c) the gender of the subjects. d) the physical coordination skills of the subjects.

In the present study the dependent variable was:

a) the length of time the subjects were deprived of sleep. b) the age of the subjects. c) the gender of the subjects. d) the physical coordination skills of the subjects.

ANSWER: Independent variable was the length of time the subjects were sleep deprived. Dependent variable was the physical coordination skills of the subjects.

EXAMPLE #2 An investigator had 60 subjects watch a videotaped

re-enactment of a bank robbery. Half of the subjects were asked by a police investigator to recall the event, while the remaining subjects were interviewed by a police investigator while they were hypnotized.

In the present study the independent variable was:

a) whether a police investigator was used. b) whether subjects were hypnotized. c) how much subjects recalled. d) what subjects watched.

In the present study the dependent variable was: a) whether a police investigator was used. b) whether subjects were hypnotized. c) how much subjects recalled. d) what subjects watched.

ANSWER: Independent variable was whether the subjects were hypnotized. Dependent variable was how much subjects recalled.

TYPES OF GROUPS Experiments can involve one or more groups

Researchers manipulate (change) the indep. var. to create the groups

Experimental Group: made up of those who are exposed to the change the indep. var. presents

Control Group: made up of those who are NOT exposed to the change Treated the exact same way though,

everything except the change

Provides a comparison against the indep. var.

Placebo: harmless substance that has no physiological effect

EXAMPLE variable- blood pressure medication independent variable- dosage dependent variable -blood pressure experimental group- group given medication control group- group given placebo

PROBLEMS Experimenter Bias: occurs when

experimenter’s expectations influence the outcome of the research

Hawthorne Effect: People tend to behave differently when they know they are being watched

Placebo Effect: Occurs when participant’s expectations, rather than the treatment, influence the outcome