Variables – Create an operational definition of the
things you will measure in your research (How
will you observe and measure your variables?)
 Population – identify the large groups you want
your research to apply to.

 Representative sample- should match the population
in question on important characteristics
 Random sampling- where each person in a research
study has an equal chance of being selected
 Volunteer bias- those who volunteer probably differ
from those that stay silent

Case Study
 Provides in-depth description of a particular
individual or event, rare occurring phenomenon
 Advantages: Unusual cases can shed light on
situations/ problems that are unethical to study in
other ways
 Disadvantages: Individual may not be
representative or typical, researcher biases

Survey/ Interview
 Research method that asks subjects questions
about their feelings, opinions or behavior patterns
 Advantages: Large amounts of information about
large numbers of people
 Disadvantages: If sample is non-representative or
biased info in inaccurate, Responses may not be
true

Naturalistic Observation
 Method that involves studying subjects without
their being award that they are being watched
 Advantages: Behavior studies is completely
natural
 Disadvantages: Researcher bias, unable to
interact with subjects, limited control

Laboratory Observation
 Method to observe behavior in a more controlled
setting
 Advantages: Allows more control and the use of
sophisticated equipment
 Disadvantages: Setting is somewhat artificial,
may not reflect the “real world”

Psychological Tests
 Objective methods for observation and
measurement of subjects in various areas
 Advantages: information gathered on personality
traits, emotional stats, aptitudes, abilities
 Disadvantages: Difficult to construct tests that
are valid and reliable

Content Analysis
 A research method that examines written data
for patterns in behavior
 Advantages: Collect large amounts of
information without having to meet subjects
 Disadvantages: limited information



A controlled test of the hypothesis
The only way to prove a cause-effect
relationship!
Manipulation of variables:
 Independent variable: the variable the
experimenter changes
 Dependent variable: a variable the experimenter
predicts will be affected by the independent
variable (in psychology it’s the behavior you are
observing)

Dividing the sample:

Experimental group: exposed to the IV
Control group: not exposed to the IV
