Research Strategies

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Chapter 2

• Research Strategies

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From Theory to Hypothesis

• Hypothesis
• Prediction about behavior
• Drawn from a theory

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Common Methods Used to Study Children

• Table 2.1
• Systematic Observation
• Natural observation
• Structured observations
• Collecting systematic observations
• Specimen record
• description of the entire stream of behavior
• Event sampling
• Record al instances of a particular behavior
  during a specified time period
• Time sampling
• Record whether a target behavior occur during a
  sample of short intervals

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Common Methods Used to Study Children

• Limitations of systematic observation
• Observer influence
• Participants act differently
• Observer bias
• Tendency of observers to see what is expected

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Common Methods Used to Study Children

• Self-reports
• Clinical interviews
• Limitations of clinical interviews
• Accuracy
• Distortion
• Flexibility in questioning
• Structured interviews, tests, and questionnaires
• Structured interview each individual is asked
  the same set of questions in the same way

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Common Methods Used to Study Children

• Psychophysiological methods
• Measurements on the involuntary activities of the
  autonomic nervous system
• Electroencephalogram (EEG)
• ERP event-related potentials
• Functional magnetic resonance imaging (fMRI)
• Clinical method (case study)

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Common Methods Used to Study Children

• Methods for studying culture
• Ethnography
• A descriptive, qualitative technique
• Participation observation

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Reliability and Validity

• Reliability
• Consistency (repeatability) of measures of
  behavior
• Validity
• Extent to which methods accurately measure what
  investigator set out to measure
• Internal validity
• The degree to which conditions internal to the
  design of the study permit an accurate test of
  the researchers hypothesis or question
• External validity
• the degree that findings generalize to settings
  and participants outside the original study

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General Research Designs

• Correlational design
• Relationships between variables
• No cause and effect
• Correlation coefficient (Fig 2.1)
• Magnitude strength of relationship
• Sign ( or -) direction of relationship

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General Research Designs

• Experimental design (Fig 2.2)
• Independent variable
• Dependent variable
• Effect of manipulating independent variable
• Laboratory experiment (Fig. 2.3)
• Confounding variables
• Random assignment
• Matching

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General Research Designs

• Modified experimental designs
• Field experiments
• Do experiment in natural settings
• Natural, quasi-, experiments (Fig. 2.5)
• Already existing treatments

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• Table 2.2

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Designs for Studying Development

• Longitudinal design
• Studied repeatedly at different ages
• Advantages of longitudinal design
• Disadvantages of longitudinal design
• Biased sampling
• Selective attrition
• Practice effects
• Cohort effects

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Designs for Studying Development

• Cross-sectional design
• Participants of different ages studied at the
  same point in time

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Improving Developmental Designs

• Combining longitudinal and cross-sectional
  approaches
• Longitudinal-sequential design
• Figure 2.6
• Microgenetic design
• Table 2.3

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Ethics in Research on Children

• Risks-versus-benefits ratio
• Protection from harm
• Informed consent
• Debriefing
• Table 2.4

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End of Chapter 2