Name _________________________________ Date _________________________ Period ___________
Psychological Research Methods and Statistics Notes
Part 1
Pre-Research Decisions:
1. Form a research question
2. Select a research method
3. Identify the sample
Sample – the ___________ group of participants, out of the total number
available, that a researcher studies
- Must be representative of the population a researcher is studying.
- How to avoid a nonrepresentative sample:
o Random sample – each individual has an ___________ chance of
being selected
 Ex: Drawing names or every 20th person
o Stratified sample – subgroups in the population are represented
proportionally
 Ex: School children – gender, race, age
Methods of Research
Naturalistic observation – research method in which the psychologist observes
the subject in a natural setting without interfering
- Example: Jane Goodall observing chimps in the wild daily
Case study – research method that involves an intensive investigation of one or
more participates (long-term)
o Results are __________ to the individual and cannot be generalized
to anyone else.
o Provide descriptive information that can generate new hypotheses.
Survey – research method in which information is obtained by asking many
individuals a fixed set of questions
o Interview, questionnaires, or a combination
 What are the benefits of using an interview?
 What are the benefits of using a questionnaire?
Longitudinal study – Research method in which data is collected about a group of
participants over a ______________________________to assess how certain
characteristics change or remain the same during development
 Good for examining consistencies and inconsistencies in behavior over
time.
 Ex: NY Longitudinal Study beginning in 1956
o Followed 133 infants to adulthood.
o Discovered that children are born with different temperaments.
Cross-sectional study – research method in which data is collected from groups of
participants of different ages and compared so that conclusions can be drawn
about differences due to age.
o Why could this study be better than a longitudinal study?
Correlation- the measure of a ______________________ between two variables
or sets of data
o Ex: There is a positive correlation between IQ scores and academic success.
o Ex: There is negative correlation between the number of hours you practice
shooting free throws and the number of times you miss.
o Correlation is NOT cause and effect.
Experiments
o Why would a researcher choose experimentation over the other research
methods?
o Hypothesis - an educated guess about the relationship between two
variables
 What you expect to find.
Variable – any factor that is capable of ___________________
 Independent variable – the one that experimenters change or
alter so they can observe its effects.
 Dependent variable – the one that changes in relation to the
independent variable.
 Ex: The number of hours you study (independent v.)
affects your performance on an exam (dependent v.)
o Experimental group- the group to which the __________________
variable is applied.
o Control group – the group that is treated is treated in the same way
as the experimental group except that the experimental treatment
(the independent variable) is not applied.
Ethical Issues
Ethics - methods of conduct or standards for proper and responsible behavior.