Ch. 2n Research Method: Tools for Discovery
Getting started: Formulating Hypotheses, Asking Questions
-operationalization: defining a concept so that it is observable and measurable
-construct: an idea or concept, especially a complex one
-following the scientific method, social development, researchers sue 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 involved 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
-independent variable: the factor that researchers deliberately manipulate in an experiment
-dependent variable: the factor that researchers expect change as a function of change in the ind.
-ecological validity: the degree to which a research study accurately represents events or processes that
occur in the real world
-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
Field Experiments, Interventions, and Natural Experiments
-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 ind. Variable and
other factors that could affect behaviour
-observer bias: an observer’s tendency to be influenced by knowledge about the research design or
-intervention: a program provided to improve a situation or relive psychological illness or distress
Combining different methods
-lab and field designs can be combined to permit the introduction of the ind. Variable in the field and
measurement of the dep. Variable in the lab, or the ind. Variable can be introduced in the lab and dep.
Outcome is measured in the field
Case Study Approach
-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
Studying 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 sm
children at different times in their lives
-disadvantages are 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 individuals from different ethnic or
social class groups are represented in the same proportions as they exist in the population
Selecting a Sample
-representative sample: a research sample in which participants are drawn from strata or categories
(ex. Social classes or ethnic groups) in the same proportions as they are found in the larger population
-samples should be representative.
-stratified sampling can be sued 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 (ex.
National Survey Approach)
-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
-effect size: an estimate of the magnitude of the difference between groups or the strength of the
association between factors, averaged across studies, in a meta-analysis
-select samples from different cultures is effective for studying development cross-culturally
Self and informant reports
-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
-self-reports are trustworthy
-experience sampling method (ESM): a data collection strategy by which participants are signalled at
random times throughout the day and record answers to researchers questions.
-the accuracy of reports from parents, siblings, teachers, or peers can improved b focusing on rece