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The Science of Change

August 15, 2012 by  

The science of measuring change

How do you measure change?

Developmental psychology is a science of change. It is the systematic study of how people change, including prenatal, childhood, adolescence, adulthood and death. The challenge is how to measure change.

Applying the scientific method to studying change is hard. It works best when the theories are clear, the models precise and the dependent variables operational defined. As we’ll see, this rarely happens.

Here’s what is included in this lesson:

  • Theories vs. models
  • Levels of measurement
  • Criteria for a good theory
  • Documentation & observation
  • Experiments & correlational studies

Read chapter 1 of Berk’s Development Thru The Lifespan

Here are the resources you need:

CLUSTER

SLIDES

TERMS

[dropdown_box expand_text=” Terms To Know” show_more=”More” show_less=”Less” start=”hide”]

  • age-graded influences = choices tend to happen at particular ages (marriage, retirement)
  • applied research
  • basic research
  • behavior modification = Thorndike, focus is on changing behaviors
  • behaviorism = reaction to psychoanalysis; emphasis on observable behaviors
  • case history
  • case study
  • causal modeling
  • cause-effect
  • chance
  • characteristics of a theory
  • chronosystem = Bronfenbrenner, cumulative lifetime experiences
  • clinical interview
  • clinical method (case study) = interviews and observations of an individual, infer broader application
  • cognitive-developmental theory = emphasis is on how thinking changes during development
  • cohort effects
  • conclusions
  • constructs
  • contexts = environment within which events occur
  • continuous development = opposite of stage theories, emphasis is on gradual ongoing changes
  • controls
  • correlation
  • correlation coefficient
  • correlational design = experiment without manipulation of independent variable
  • criterion
  • cross-sectional design = study people from different age groups at same time
  • cross-sectional studies
  • data
  • data collection methods
  • delayed treatment
  • dependent variable
  • descriptions
  • developmental cognitive neuroscience = interdisciplinary study of neural changes during development
  • developmental science = scientific study of changes over the entire lifespan
  • discontinuous development = stage theories of development
  • documentation
  • ecological systems theory = Bronfenbrenner; influence of environmental systems & sub-systems
  • emic perspective
  • ethnography
  • ethology = scientific study of animal behavior
  • etic perspective
  • evolutionary developmental psychology = comparative psychology, focus on how behaviors are evolutionarily advantageous; study genetic and ecological mechanisms
  • exosystem = Bronfenbrenner, external influences on microsystems, unemployment, etc.
  • experimental design
  • experimentation
  • explanations
  • group data
  • history-graded influences = correlated with wars, famines and epidemics
  • independent variable
  • inferences
  • information processing = emphasis on active processing of info, not just reacting to it
  • internally consistent
  • inter-rater reliability
  • interval scale
  • interviews
  • leading questions
  • lifespan perspective = focus is on whole life, not focusing only on childhood or adolescencce
  • longitudinal design = measuring the same people over time
  • longitudinal studies
  • macrosystem = Bronfenbrenner, cultural norms, political conditions
  • magnitude
  • mesosystem = Bronfenbrenner, interactions between mircosystems
  • meta-analysis
  • microsystem = Bronfenbrenner, where you live, family, peers
  • model
  • Morgan’s Cannon
  • naturalistic observation
  • nature–nurture controversy = either-or argument for heredity or environment
  • necessary
  • negative correlation
  • nominal scale
  • nonnormative influences = things that happen to one person
  • normal curve
  • normative approach = use normal curve to describe development by what most can do at given age
  • observations
  • observer effect
  • open-ended questions
  • operational definition
  • ordinal scale
  • organizing frameworks
  • outcome measure
  • paired observations
  • participant observation
  • positive correlation
  • practice effects
  • predictor
  • properties
  • psychoanalytic perspective = Freud’s psychodynamic theory of unconscious motivations
  • psychosexual theory = Freud, stages of childhood development: oral, anal, phallic, latency & genital
  • qualitative
  • quantitative
  • questionnaires
  • random assignment
  • random selection
  • rank scale
  • ratio scale
  • repeated measures
  • replication
  • resilience = ability to recover from negative influence
  • scientific method
  • script
  • self-report
  • sensitive period = critical period, phase when a small dose can cause great damage
  • sequential designs
  • shared variance
  • sign
  • significance
  • small number of assumptions
  • social learning theory = Bandura, people learn in a social context, a reciprocal interaction
  • sociocultural theory = Vygotsky, develop first on social level, then on individual levels
  • split-plot
  • stage = assumes everyone goes through same phases in the same order
  • structured interview
  • structured observation
  • subject loss
  • sufficient
  • summarize facts
  • symmetrical
  • systematic underrepresentation
  • testable hypotheses
  • theory
  • useful
  • variables
  • verification
  • zero correlation

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NOTES

[dropdown_box expand_text=” For You” show_more=”Notes” show_less=”Less” start=”hide”]

  • Scientific Method
    • Observations = what senses tell
    • Inferences = conclusions drawn
    •  Theories: constructs
    • Models: variables
  •  Theories include:
    • Explanations
    • Descriptions
    • Predictions
  •  6 Characteristics of a theory
    • 1. Clear
      • Skinner is clear
      • Piaget is not
    • 2. Useful
      • Skinner & Piaget are useful
    • 3. Summarize facts
      • Organizing frameworks
      • Babylonian creation story
      • Jewish creation story
      • Theory of evolution
    • 4. Small number of assumptions
      • Morgan’s Cannon
    • 5. Internally consistent
      • Piaget is not consistent; written over many years
    • 6. Testable hypotheses
  • Verification: Did you see that?
  • Replication: Do it again?
    • Application:
      • What foods to eat
      • Acupuncture
      • Spankin
  • Theories determine
    • Which variables to study
    • What they look like (properties)
    • How they inter-relate
    • How to measure them
  •  Operational Definitions
    • Define in terms of operations
    • What is done
  • Chance & not chance
    • Normal curve
    • Symmetrical
    • Most people in the middle
  • 4 ways to use numbers
    • Nominal = use as names
    • Ordinal = place, rank or rating
    • Interval = count
    • Ratio = math numbers
  • Developmental Research
    • Hard to measure change
    • Too fast
    • Too slow
  • Principles
    • Qualitative vs quantitative
    • How ask question makes diff
    • Systematic underrepresentation
    • Lack of language
    • Some important behaviors are rare
  • Approaches to Research
    • Basic = improve theory
    • Applied = improve application
  • Data Collection Methods
    • 1. Documentation
      • Baby biographies
      • Diaries
    • 2. Observation
      • A. Naturalistic observation
        • Advantages
          • Non-lab environment
          • Less “artificial”
        • Disadvantages
          • Observer effect
          • Affected by presence of observers
      • B. Ethnography
        • in-depth descript of how live
        • emic perspective (insider’s)
        • etic perspective (outsider’s)
        • participant observation (long-term field study)
      • C. Structured observation
        • Advantages
          • Relatively naturalistic
          • Some lab-based controls
        • Disadvantages
          • Time consuming
          • Subjective results
          • Inter-rater reliability
      • D. Case history (case study)
        • Freud
      • E. Cohort effects
        • Baby Boomers
    • 3. Self-report
      • A. Questionnaires
        • Given to parents, friends, teacher…
        • Advantages
          • Convenient
          • Cheap
        • Disadvantages
          • Social desirability
          • Lack of objectivity
      • B. Interviews
        • Clinical interviews
        • Structured interviews
        • Targeted data (specific questions, open-ended)
        • Advantages
          • Can follow up kid’s answers
          • Probe topics of interest
          • Not stuck with ‘script’
        • Disadvantages
          • Diff. questions for each child
          • Difficult to generalize results
          • Experimenter demands
          • Leading questions
    • 4. Correlation
      • Relationship between variables
      • Paired observations
      • Simple correlations & used in Causal Modeling
      • Not prove cause-effect
        • Necessary, not sufficient
        • 4 possible interpretations
          • A can cause B
          • B can cause A
          • C can cause A & B
          • Chance
      • Significance
        • Relationship unlikely to be due to chance
        • Unlikely, not impossible
        • Shared variance: what have in common
      • Examples
        • Skill in baseball and shoe size
        • Shirt length and stock market prices
        • Ice cream sales and rates of drowning
        • Length of marriage and male baldness
        • Cause-effect inferences are at your own risk
      • Correlation Coefficient
        • Sign
          • Positive = When X goes up, Y goes up
          • Negative = When X goes up, Y goes down
          • Zero = When X goes up, Y wanders aimlessly
        • Magnitude
          • Between -1 and +1
          • Amount of relationship
    • 5. Experimentation
      • Observations (data)
      • Independent variable
        • Experimenter controls variable
        • Independent of the subject
        • Predictor
      • Dependent variable
        • Under control of subject
        • Outcome measure
        • Criterion
      • Random selection
        • Equal likelihood of being studied
      • Random assignment
        • Equal chance of getting wonder cure
      • Cause and effect inferences
        • More comfortable
        • Still inferring
    • 6. Meta-analysis
      • Comparing theories
  • Five Experimental Designs
    • A. Cross-sectional studies
      • Different groups, same time
      • 10, 20, 30 and 40 year olds
      • 1st, 3rd and 5th graders
      • Advantages
        • Snapshot
        • Least expensive
        • Quick estimate of developmental function
      • Disadvantages
        • Group data, not individual
        • Don’t know what will happen next
        • Cohort effects = not equivalent groups
        • Reading program
        • Year born
    • B. Longitudinal studies
      • Longitudinal = same group over time
      • Advantages
        • Avoid cohort effects
        • Act as own control
      • Disadvantages
        • Time consuming
        • Expensive
        • Subject loss; die, move away, quit
        • Practice effects
          • repeated exposure to a test situation
    • C. Split-Plot
      • Random assign to field (group)
      • Repeated measures (rows)
    • D. Sequential designs
      • Data collected as go
    • E. Delayed treatment
      • Group 1 right now
      • Group 2 in 6 months

[/dropdown_box]

 

 QUIZ

[dropdown_box expand_text=” For You” show_more=”Quiz” show_less=”Less” start=”hide”]

  • 1. In this scale of measurement, numbers indicate rank or order:
    • a.           nominal
    • b.           ordinal
    • c.           interval
    • d.           ratio
  • 2. Which correlation coefficient show the most relationship:
    • a.           .55
    • b.           .35
    • c.           -.77
    • d.           3.14
  • 3. Which equal opportunity to be in the study:
    • a.           random number generator
    • b.           random consolidation
    • c.           random assignment
    • d.           random selection
  • 4. The Baby Boomers are a:
    • a.           split-plot
    • b.           cohort
    • c.           SES
    • d.           gaggle
  • 5. Models are composed of:
    • a.           constructs
    • b.           variables
    • c.           theories
    • d.           ideas

For the answers: Click Here

[/dropdown_box]

 

DISCUSSION ITEM

  • What part of life do you think has the greatest amount of change?

 

 

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