THE SCIENCE OF PSYCHOLOGY

RESEARCH METHODS

1. PERCEIVING THE QUESTIONWhat do you want to know about?

2. FORMING A HYPOTHESISWhat is my educated guess?

3. TESTING THE HYPOTHESIS What method of research should I use?

4. DRAWING CONCLUSIONSHow do I use statistics to draw conclusions?

5. REPORT YOUR RESULTSShare with others, allow for replication

SCIENTIFIC METHOD: a system for reducing bias and error in the measurement of data

http://www.freedigitalphotos.net/images/view_photog.php?photogid=4112">Image: metrue / FreeDigitalPhotos.net

Do opposites attract?

OR,

Do birds of a feather flock together?

Simply wants to gather information

Gives a detailed description

Observes and records

Does not seek to show relationships

DESCRIPTIVE METHODS:

Best way to look at behavior of animals or people

In natural environmentAdvantage: realistic picture of behavior because you

are seeing it happenDisadvantages:

-observer bias: see what expect to-observer effect: act differently because being watched

http://www.freedigitalphotos.net/images/view_photog.php?photogid=1058">Image: Arvind Balaraman

Naturalistic Observation:

When observation in a natural setting is not practical

NOT AN EXPERIMENTAdvantages: gives more control to

researcherDisadvantages: artificial setting means may

not reflect behavior in “real world”

Laboratory Observation:

http://www.freedigitalsphotos.net/images/view_photog.php?photogid=1499">Image: Ambro / FreeDigitalPhotos.net

One individual/small group are studied in great detail

Uses all other methods of research Usually unusual/rare cases

Advantage: lots of detail/information Disadvantage: low generalizability-can’t

really be applied to others

Case Study:

http://schoolswikipedia.org/images/526/52611.jpg

Ask questions about topic you are studying Questionnaires, interviews, on internet Can ask about embarrassing/personal info Advantages: lots of information from large

group of people, quick results, inexpensive Disadvantages: Social desirability bias: people want to look good Volunteer bias: people who participate are

different Framing: way word questions can affect answers

Survey:

When choosing participants, can’t survey everyone from population

Must choose people to be representative of whole group

Random sample: everyone in the population has an equal chance to be in study

More people, randomly chosen means more likely to be representative

Generalizability: how well sample represents target population, do results apply to all?

Sampling:

Seeks relationship between 2 variables Does NOT want to prove cause/effect Positive correlation: variables increase in

the same direction more studying, better grades

Negative correlation: variables have an inverse relationship more smoking, worse health

Illusory correlation: no real relationship existssugar and hyperactivity

CORRELATIONAL METHODS:

Statistics that show strength of the relationship between variables

Perfect positive correlation = +1 Perfect negative correlation = -1 No correlation = 0

-1---------------0--------------+1

Further from 0 = stronger the relationship

Correlation coefficients:

Graph to show correlations

Scatter plots:

0 1 2 3 4 5 6 7 8 90123456789

Weight loss

EXPERIMENTAL METHOD:

IT IS THE ONLY METHOD THAT CAN SHOW A CAUSE AND EFFECT RELATIONSHIP BETWEEN 2 VARIABLES

Researchers manipulate the variable they think is causing the change and then they

CONTROL everything else but that variable,

IF the other variable changes then they know it was due to their manipulation.

CAUSE AND EFFECT

HOW?

Do violent cartoon showscause children to bemore aggressive?

EXAMPLE:

http://commons.wikimedia.org/wiki/File:Bugs_Bunny_-_Fresh_Hare_(_any_1942).JPG

Independent variable: the variable being manipulated by the researcher

Dependent variable: the variable that is being measured for change

Operational Definitions: how the variables are going to be measured and quantified so that the research can be replicated

Variables:

IV: violent cartoons (what the researchers will control and manipulate)

Operational definition: What makes a cartoon violent? How many acts of violence? Must quantify.

DV: aggressive behavior (what they want to measure)

Operational definition : What is an aggressive act? How will they know if a kid is more aggressive or less?

Other factors that can affect the Independent Variable OTHER THAN the Dependent Variable

Don’t allow for Cause-Effect conclusion

Exs.: kid’s home-life, natural temperament, grumpy that day, hungry, tired, don’t like

cartoons, mad they have to be in an experiment

How to control for these??

Confounding variables:

Experimental group: get the experimental manipulation (watch the violent cartoon)

Control group: don’t get the manipulation, there only for comparison (watch a nonviolent cartoon)

MUST BE ALIKE IN EVERY OTHER WAY Random assignment: must have an equal

chance of being in the control or experimental groups

Groups:

Placebos: fake treatments -placebo effect: expectations of participants

can influence their behavior Single-blind: participant doesn’t know if in

control or experimental group -subject bias: tendency to act how they think

they are supposed to act Double-blind: neither participant nor

researcher knows the group -experimenter bias: researcher

unintentionally influences the study

Some Other controls:

Participants in research have the right to expect that no physical or psychological harm will come to them.

Guidelines are established by the American Psychological Association

Institutional Review Boards: check over the proposed research for ethical concerns and for any flaws in the design

Ethical concerns:

Why use animals? Shorter lives = long-term effects sooner Easier to control Simpler behavior=easier to see

manipulations Can do things to animals can’t do to

humans

Least amount of harm possible

Animal research:

1. informed consent 2. deception must be limited and justified 3. participants can withdraw at any time 4. confidentiality must be maintained 5. no long-term mental risk 6. no physical risk 7. debriefing

Research with people: