Chapter 2
Research Methods: Tools for Discovery
Chapter Outline
RESEARCH METHODS: TOOLS FOR DISCOVERY
GETTING STARTED: FORMULATING HYPOTHESES, ASKING
QUESTIONS
RESEARCH METHODS: ESTABLISHING PATTERNS AND CAUSES
THE CORRELATIONAL METHOD
LABORATORY EXPERIMENTS
FIELD EXPERIMENTS, INTERVENTIONS, AND NATURAL EXPERIMENTS
Field Experiments
Interventions
Natural Experiments
Insights from Extremes: Lost and Found Children
COMBINING DIFFERENT METHODS
THE CASE STUDY APPROACH
Real-World Application: Treating an Aggressive Child
STUDYING CHANGE OVER TIME
The Cross-Sectional Design
The Longitudinal Design
Into Adulthood: Behavior in Childhood Predicts Adult Outcomes
Learning from Living Leaders: L. Rowell Huesmann
The Sequential Design
SELECTING A SAMPLE
Representativeness of the Sample
The National Survey Approach
Meta-Analysis: Combining Results across Studies
Studying Development Cross-Culturally
Cultural Context: Challenges for Researchers
GATHERING DATA
CHILDREN’S SELF-REPORTS
Research up Close: The Puppet Interview Method
Learning from Living Leaders: Reed Larson
REPORTS BY FAMILY MEMBERS, TEACHERS, AND PEERS
Family Members
Bet You Thought That . . . Parents Can Accurately Report Their Children’s Early Years
Teachers and Peers
FOCUS GROUPS
DIRECT OBSERVATION
Naturalistic Observation
Structured Observation
WAYS OF RECORDING AND CODING OBSERVATIONS
Behavior Observations
Ethnographic Approaches
Learning from Living Leaders: Linda M. Burton
Nonverbal Measures
Internal Responses
Learning from Living Leaders: Megan Gunnar
ANALYZING DATA
ETHICS OF RESEARCH WITH CHILDREN
CHAPTER SUMMARY
KEY TERMS
At the Movies
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Learning Objectives
1. Describe the scientific method as a means for testing hypotheses and answering questions.
2. Compare correlational and experimental methods. Discuss when each method is appropriate to
use and provide examples.
3. Understand the limitations of a laboratory experiment with regard to ecological validity and
how a laboratory analogue experiment may address this weakness.
4. Describe both field and natural experiments and the strengths and weaknesses of each.
5. Explain how a laboratory and field experiment can be combined.
6. Describe the case study approach and reasoning for using this approach.
7. Describe the cross-sectional, longitudinal, and sequential methods for studying change over
time. Explain the different types of information each of these approaches yields about
development and the strengths and weaknesses of each method.
8. Describe the importance of sampling and specifically define what is meant by representative
sample.
9. Describe the various methods of gathering data (e.g., self-reports, reports by others, focus
groups, observations) and the strengths and weaknesses of each.
10. Understand the advantage to using a combination of methods and designs in developmental
research.
11. Describe the difference between quantitative and qualitative studies.
12. Explain why it is important to protect children’s rights when conducting research. Discuss
special ethical issues that should be considered (i.e., informed consent), and what precautions
are taken to ensure that children are protected.
Student Handout 2-1
Chapter Summary
Scientific Method, Hypotheses, and Questions
 Following the scientific method, social development researchers use reliable and replicable
techniques to collect and analyze data to answer their questions or test their theory-based
hypotheses.
Research Methods: Correlations and Experiments
 The correlational method involves computing associations between pairs of variables,
varying from –1.0 to + 1.0. Correlated variables are related to each other, but one does not
necessarily cause the other.
 A laboratory experiment permits a researcher to establish a causal association by
manipulating the independent variable and assessing the effect on the dependent variable in a
controlled setting. Researchers randomly assign participants to experimental and control
groups.
 One way to increase ecological validity is to conduct a laboratory analogue experiment,
trying to duplicate in the laboratory features or events from everyday life.
 Another way to increase ecological validity is to conduct a field experiment, deliberately
producing a change in a real-life setting and measuring the outcome.
 In a natural experiment, the investigator measures the effect of a naturally occurring change.
 Interpreting the results is often difficult because the researcher lacks control over the
independent variable and other factors that could affect behavior.
 Lab and field designs can be combined to permit the introduction of the independent variable
in the field and measurement of the dependent variable in the lab, or the independent variable
can be introduced in the lab and the dependent outcome is measured in the field.
 The case study method takes an in-depth look at a single child or a small group of children
who often have some uncommon feature that makes them of special interest.
Study of Change over Time
 In the cross-sectional method, researchers compare groups of children of different ages.
 This approach is economical, but it yields no information about change or causes of change.
The longitudinal method overcomes these two drawbacks because the researcher examines
the same children at different times in their lives. Longitudinal research has disadvantages
that include high cost, loss of subjects, untested age cohort effects, and limited flexibility to
incorporate new measures.
 The sequential method combines features of cross-sectional and longitudinal studies and
enables researchers to compare groups of children of different ages, track individual children
as they get older, and compare age cohorts.
Sample Selection
 Samples should be representative of the population of interest to the researcher. Stratified
sampling can be used to ensure that subgroups of boys and girls or individuals from different
ethnic or social class groups are represented in the same proportions as they exist in the
population.
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Data Collection and Analysis
 Self-reports provide information about children’s thoughts, attitudes, and feelings. In the
experience sampling method, a “beeper” signals children to record their activities, thoughts,
and emotions at random times.
 The accuracy of reports from parents, siblings, teachers, or peers can be improved by
focusing on recent events and using structured procedures such as daily diaries, phone calls,
or beeper methods.
 A focus group allows children or adults to share their views about different aspects of
children’s social experience. This strategy is especially useful in the early stages of a
research project or with a new cultural group.
 Observations can occur in natural settings, such as a child’s home, or in a laboratory. One
limitation is that when children and parents know they are being watched, they act in more
socially acceptable ways. To minimize such distortions, researchers try to observe
unobtrusively for relatively long periods. A structured observation allows researchers to
observe children performing in specific situations that occur infrequently in normal everyday
life.
 Researchers can record everything the participant does (a specimen record), record only
particular events (event sampling), identify which behaviors of a predetermined set occurred
during a particular time period (time sampling) or record events in order of occurrence
(sequential observation).
 Ethnographic data collection involves becoming a participant observer by spending time with
community members and recording information about their activities and the setting.
 To study infants, who cannot express their thoughts and preferences verbally, researchers use
nonverbal responses such as visual preferences, habituation to stimuli, physical movement,
and sucking patterns.
 Psychophysiological assessments of heart rate, respiration rate, brain activity, and hormone
levels are useful for obtaining information about children’s responses to social situations and
stress.
 In qualitative studies, researchers search for meaningful themes in transcripts of interviews or
participant observations. In quantitative studies, statistical analyses are performed to
determine differences between groups of children or associations between variables. Multiple
regression analyses are used to examine associations among a number of variables.
Ethics
 Ethical issues are a major consideration in research on children. Guidelines for ethical
treatment include the right to informed consent and the right not to be harmed. To determine
whether research procedures are ethical, costs to participants are carefully weighed against
the potential benefits to the participants or society.
Student Handout 2-2
Key Terms
GLOSSARY TERMS
case study
A form of research in which investigators
study an individual person or group intensely.
construct
An idea or concept, especially a complex one
such as aggression or love.
cortisol
A hormone secreted by the adrenal glands in
response to any kind of physical or
psychological stress.
cross-sectional design
A research design in which researchers
compare groups of individuals of different age
levels at approximately the same point in time.
dependent variable
The factor that researchers expect to change as
a function of change in the independent
variable.
direct observation
Researchers go into settings in the real world
or bring participants into the laboratory to
observe behaviors of interest.
ecological validity
The degree to which a research study
accurately represents events or processes that
occur in the real world.
effect size
An estimate of the magnitude of the difference
between groups or the strength of the
association between the factors, averaged
across studies in a meta-analysis.
ethnography
Use of intensive observations and interviews to
gather data about the beliefs, practices, and
behaviors of individuals in a particular context
or culture.
event sampling
Investigators record participants’ behavior only
when an event of particular interest occurs.
experience sampling method (ESM)
A data collection strategy by which
participants are signaled at random times
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throughout the day and record answers to
researchers’ questions, such as: Where are
you? Who are you with? What are you doing?
Also called the beeper method.
field experiment
An experiment in which researchers
deliberately create a change in a real-world
setting and then measure the outcome of their
manipulation.
focus group
Group interview in which an interviewer poses
questions that are answered by the participants.
habituation
An individual reacts with less and less intensity
to a repeatedly presented stimulus until he or
she responds only faintly or not at all.
hormone
Powerful and highly specialized chemical
substance produced by the cells of certain body
organs, which has a regulatory effect on the
activity of certain other organs.
independent variable
The factor that researchers deliberately
manipulate in an experiment.
informed consent
Agreement to participate in that study based on
a full understanding of its purposes and
procedures.
intervention
A program provided to improve a situation or
relieve psychological illness or distress.
laboratory analogue experiment
Researchers try to duplicate in the laboratory
features or events that occur naturally in
everyday life in order to increase the ecological
validity of the results.
longitudinal design
A study in which investigators follow the same
people over a period of time, observing them
repeatedly.
meta-analysis
A statistical technique that allows the
researcher to summarize the results of many
studies on a particular topic and to draw
conclusions about the size and replicability of
observed differences or associations.
natural experiment
An experiment in which researchers measure
the results of events that occur naturally in the
real world.
naturalistic observation
Information collected in the child’s natural
settings, at home, in child care, or in school
without interfering with the child’s activities.
observer bias
An observer’s tendency to be influenced by
knowledge about the research design or
hypothesis.
operationalization
Defining a concept so that it is observable and
measurable.
participant observation
Research strategy used to gain familiarity with
a group of individuals by means of
involvement in their activities, usually over an
extended period of time.
Physiological bases of psychological processes
measured by brain activity, brain waves, and
heart rate.
psychophysiological
qualitative study
Research using nonstatistical analysis of
materials gathered from a relatively small
number of participants to gain an in-depth
understanding of behavior and contexts.
quantitative study
Research involving statistical analysis of
numerical data.
reactivity
The change in a person’s behavior due to the
fact that he or she is being observed.
representative sample
A research sample in which participants are
drawn from strata or categories (e.g., social
classes or ethnic groups) in the same
proportions as they are found in the larger
population.
self-report
Information that people provide about
themselves either in a direct interview or in
some written form, such as a questionnaire.
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sequential design
A way of studying change over time that
combines features of both cross-sectional and
longitudinal designs.
specimen record
Researchers record everything a person does
within a given period of time.
structured observation
A form of observation in which researchers
create a situation so that behaviors they wish to
study are more likely to occur.
time sampling
Researchers record any of a set of
predetermined behaviors that occur within a
specified period of time.
OTHER IMPORTANT TERMS IN THIS CHAPTER
control group
deception
eavesdropping technique
EEG
experimental group
family stories
generalizability
interpretative validity
mediation
MRI
negative correlation
observed sequences
oversampling
path analysis
PET
positive correlation
practice effects
puppet interview
quasi-experiment
representativeness
story completion technique
structured diary
survey approach
Student Handout 2-3
Design a Research Study
1. Hypothesis:
2. Data collection method (assigned by instructor):
3. Research design (correlational or experimental):
4. Design for studying change over time (cross-sectional, longitudinal, sequential):
5. Independent variables:
6. Dependent variable:
7. Procedures:
8. Tasks or instruments:
9. Subjects (describe who and how they will be selected):
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Student Handout 2-4
Age Cohorts
1.
Imagine that you want to study the effects of television viewing on social interaction
between the ages of 5 and 20. Describe the problem of different age cohorts that might
arise in a longitudinal study.
2.
Describe the problem for a cross-sectional study.
3.
How could you design the study so that you would not have a problem with age cohorts?
4.
Give another example of a research topic in which age cohorts would be a problem, and
describe how it would affect the interpretation of the results.
Practice Exam Questions
MULTIPLE CHOICE QUESTIONS
1. Which of the following is not an advantage of case studies? Case studies (a) allow the study of
rare phenomena (b) facilitate intensive investigation and details about the process under study
(c) *are easily generalizable to other individuals (d) are useful as a precursor or follow-up to
studies using other methods
2. A research design in which researchers compare groups of individuals of different age levels at
approximately the same point in time is: (a) event sampling (b) a longitudinal design (c) a
sequential design (d) *a cross-sectional design
3. The degree to which a research study accurately represents events or processes that occur in the
real world is: (a) observer bias (b) reactivity (c) effect size (d) *ecological validity
4. A data collection strategy in which participants are signaled at random times throughout the
day and record answers to researchers’ questions is called: (a) *the experience sampling
method (b) event sampling (c) participant observation (d) structured observation
5. A type of group interview in which an interviewer poses a set of questions that are answered by
the participants of the group is called: (a) a representative sample (b) a structured observation
(c) *a focus group (d) a field experiment
6. The assessment of hormone levels in the body is an example of a: (a) neurological technique
(b) self-report (c) meta-analysis (d) *psychophysiological technique
7. A type of experiment in which researchers try to duplicate in the laboratory features or events
that occur naturally in everyday life in order to increase the ecological validity of their results
is: (a) a field experiment (b) a natural experiment (c) *a laboratory analogue experiment (d) an
intervention
8. Disadvantages of longitudinal designs over cross-sectional designs include the following: (a)
they take a long time (b) participants drop out (c) they are not flexible to changing conditions
or to new assessments (d) *all of the above
9. Distortions in naturalistic observations can be reduced by: (a) conducting repeated observations
(b) using less obtrusive observational methods (c) *both a and b (d) neither a nor b
10. Qualitative studies: (a) are ideal for establishing causal effects (b) aid in generate hypotheses
(c) can help interpret findings from more objective research (d) *b and c
11. A research sample in which participants are drawn from strata or categories in the same
proportions as they are found in the larger population is: (a) cross-sectional (b) *representative
(c) ecological (d) experiential
12. A form of observation in which researchers structure a situation so that behaviors they wish to
study are more likely to occur is called: (a) *a structured observation (b) event sampling (c)
time sampling (d) specimen record
ESSAY QUESTIONS
1. Describe three advantages and three disadvantages of longitudinal designs for research
2. Why is it valuable to use a mixed methods approach, such as using qualitative and quantitative
methods, in the same study?
3. Discuss the importance of clear guidelines for the ethical treatment of children in research and
outline the main principles of ethical treatment of children.
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