I. Scientific Principles In Psychology
A. Scientific attitudes
Curiosity, Humble, Skeptical
B. Kitty Genovese Case
1. Darley and Latane (1968), two psychologists, questioned this ‘apathy’
2. Did experiments to test when people helped and when they did not.
3. Diffusion of responsibility: Found if people are alone they are more likely to help,
but if there are others around they ‘diffuse’ their responsibility by thinking
someone else will help. Also, if nobody is helping e label the situation as a
nonemergency or nonhelping situation.
Gathering evidence: Steps in the scientific process
1. Identify a question of interest
2. Gather information and form hypothesis
3. Test hypothesis by conducting research
4. Analyze data, draw tentative conclusions, and report findings
5. Build a body of knowledge
D. Hypothesis: a testable prediction consistent with our theory
1. a statement that attempts to predict or account for a set of phenomena
2. a proposed explanation for a behavior
3. can be empirically tested
4. If bystanders are present THEN the likelihood that any one bystander will
intervene is reduced.
E. Two approaches to understanding behavior
Hindsight reasoning(AftertheFact Understanding)
2. Understanding through prediction, control, and theory building
1) Broader than hypothesis
2) is an organized system of assumptions and principles that tries to explain
phenomena and how they are related
3) describes behavior and makes predications about future behavior
b. Important characteristics of a good theory
1) It organizes information in a meaningful way.
2) It is testable.
3) The predictions made by the theory are supported by the findings of new
4) It conforms to the law of parsimony: if two theories can explain and
predict the same phenomena equally well, the simpler theory is the
F. Defining and measuring variables
1. Variable: Any characteristic that can vary and be measured. a) In both correlations and experiments scientists study variables which are
characteristics that can vary. Examples are people’s height, hair colour, age,
income, GPA. But also broader concepts: Selfesteem, stress and intelligence.
b) Variables ‘varyables’ vary from one person to another and also vary within a
given person over time. Your weight varies over time and your weight varies
from your neighbor’s weight.
c) Stress, IQ, selfesteem are also iables.
2. Operational definition: Defines a variable in terms of specific procedures used to
produce or measure it.
a) Spell out exactly how we are going to transform a concept or thing into
something that can be measured.
3. Different Kinds of Measures in Psychological Research
a) Selfreports and reports by others: Ask people to report on their own
knowledge, beliefs, feelings, experiences, or behavior. This information is
often gathered through interviews or questionnaires/surveys.
b) Measure directly observable behavior
― Psychological tests: Personality test, performance task to test for
― Psychological measures: Heart rate, blood pressure, hormones to test for
stress. Reaction time or brain functioning to test memory.
― These observations done by scientists need to be reliable—two researchers
seeing the behavior codes for it in the same way.
II. Methods Of Research
A. Descriptive research: Recording events
1. Descriptive Methods are used to systematically observe and describe behavior
a) Case studies: Examines one individual or social unit in depth in the hope that
the findings can be generalized
b) Survey research: Asking people to respond in depth to a series of questions
or to report on their behavior
c) Naturalistic observation: Observing and recording behavior as it occurs in its
2. Some drawbacks to these methods
a) Case studies: The case study may be too narrow to be of general use.
b) Survey research: People may not respond accurately to surveys or may be
c) Naturalistic observation: Naturalistic observations may not reveal all the
factors that contribute to the observed behavior.
B. Types of descriptive research
1. Case study
a) A detailed description of one person, small group or event.
b) Benefit: can be a source of ideas about human nature in general. Used to
formulate a broader research hypothesis.
c) Drawbacks: Do NOT inform about cause and effect. Can’t generalize results
to other people or situations. Based on observer's subjective impressions. 2. Naturalistic Observation
a) Observational studies are systematic observation and the recording of people
b) Observe “natural” behavior means just watching (and taking notes), and
not trying to change anything. Can be in natural environment like home or
c) This method can be used to study more than one individual, and to find
truths that apply to a broader population.
3. Survey Research
a) Definition: A method of gathering information about many people’s
thoughts or behaviors through selfreport rather than observation.
Questionnaires, interviews that ask people about experiences, attitudes,
b) Keys to getting useful information
c) Be careful about the ording of questions.
d) Wording effects: The results you get from a survey can be changed by your
word selection. Biased assumptions can be built into wording.
e) Remember: No cause and effect conclusions with a survey
C. Population and sample
1. Population: All individuals whom you are interested in drawing a conclusion
2. Sample: Is a subset of individuals from that larger population
D. Random sampling
1. Is a technique for making sure that every individual in a population has an equal
probability of being chosen to participate in your study, of being in your sample.
2. “Random” means that your selection of participants is driven only by chance not
by any characteristic.
E. Clarify random sampling and representative sample
1. Random sampling: Every member of a population has the same probability of
being asked to participate in your survey, experiment, or other method (except
2. Representative sample: A sample of participants who reflect the important
characteristics of the population. Can’t have all men if your class has men and
III. Two Different Ways To Measure Behavior: Correlations & Experiments
A. Correlational research: Measuring associations between events
a) General Definition: An observation that two or more variables are related
to one other. Thus, they are “co”related.
b) Scientific definition: A measure of how closely two factors vary together,
or how well you can predict a change in one variable from observing a
change in the other.
2. Correlational research
a) A correlational research is a NOT an experiment. It falls under descriptive research because it does NOT establish causation. This research provides a
statistic that DESCRIBES if there is a relationship between two or more
variables. This statistic also describes how strongly 2 or more variables are
b) Correlation Coefficient (called the Pearson R) tells us how strongly two or
more variables are related, the direction of that relationship (positive or
negative), and thus how well one variable predicts the other. Height and
weight have a strong, positivecorrelation—the taller you are the more you