Research Methods

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Research Methods

• Psychology 117

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Research Questions

• Does playing violent videogames produce
  aggression in children?
• What are the long-term effects of early
  malnutrition?
• How do children of different ages react to a
  divorce of their parents?

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Origins of Assumptions and Beliefs?

• Word-of-Mouth Folklore
• Friends and relatives
• Portrayals of children/families on TV/books
• Religious teachings
• Talk shows
• Personal Experiences
• Expert Opinions
• Research Evidence

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Research evidence is valuable because results are

• Observations of many children
• Unbiased observers
• Reliable, valid methods of measurement
• Careful control

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Theories

• An orderly, integrated set of statements that
  describes, explains, and predicts behavior
• Vital tools
• Guide and give meaning
• Practical action

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• Theories ? hypotheses
• Predictions about behavior
• Research Question vs. Hypothesis
• Need plan (research design) for conducting
  specific activities (research method)

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• Examine whether a relationship exists between
  variables
• Independent Variable
• Dependent Variable
• Does eating candy produce hyperactivity?
• Does playing violent videogames produce
  aggression in children?
• Does drinking wine lower your risk for heart
  disease?
• Does exposure to smoke increase the risk of SIDS?

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• Statistical Significance
• Reliability consistency
• Validity
• External/ecological validity
• Internal validity

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Correlational Research

• The Correlational Design
• 2 or more variables meaningfully related
• Correlation coefficient (r)
• 1.00 to -1.00
• Sign indicates direction
• Positive ()
• Negative (-)

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• Figure 1.2 Plot of a hypothetical positive
  correlation between the amount of violence that
  children see on television and the number of
  aggressive responses they display. Each dot
  represents a specific child who views a
  particular level of televised violence (shown on
  the horizontal axis) and commits a particular
  number of aggressive acts (shown on the vertical
  axis). Although the correlation is less than
  perfect, we see that the more acts of violence a
  child watches on TV, the more inclined he or she
  is to behave aggressively toward peers.

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Correlational Research

• Correlational studies ? causation.
• Causal direction unknown
• Could be due to a third, unmeasured (confounding)
  variable

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Experimental Design

• Cause/effect
• Systematically manipulate a variable
• Random assignment
• Control group
• Experimental/treatment group(s)
• Hold conditions constant
• Eliminate threat of confounding variables

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Field Experiment

• Natural setting
• Example in text Belgian delinquents living in
  minimum-security institution for adolescent boys

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• Figure 1.3 Mean physical aggression scores in the
  evening for highly aggressive (HA) and less
  aggressive (LA) boys under baseline conditions
  and after watching violent or neutral movies.
  ADAPTED FROM LEVENS ET AL., 1975.

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Field Experiment

• May not be aware that they are participating

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• Study the effects of malnutrition or sensory
  deprivation on infant motor development.
• Volunteers?

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Natural/Quasi-Experiment

• Naturally occurring events
• No manipulation of variables
• No random assignment

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• Table 1.4 Strengths and Limitations of General
  Research Designs

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Self-Report Methodologies

• Interviews/Questionnaires
• Unstructured to structured
• Difficult with children
• Clinical Method
• Can ask follow-up questions specific to
  individual being interviewed (thus, less
  structured)

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Self-Report Methodologies

• Limitations
• Honesty/accuracy
• Interpretation of questions
• Use with children
• Strengths
• Efficient (large amounts of data, short amount of
  time)
• Confidentiality improves accuracy

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Observational Methodologies

• Naturalistic Observation
• Observations in common, everyday (i.e., natural)
  settings
• Strengths easy, behavior is natural
• Thus _________ validity is high
• Limitations frequency of behavior reactivity

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Observational Methodologies

• Structured Observations
• Laboratory setting
• Set up a scenario
• Strengths same environment, attempt to elicit
  low frequency behaviors
• Limitations external validity?

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Case Study

• a detailed portrait of a single individual can
  also describe groups
• Strength depth
• Limitations
• Difficult to compare
• Generalizability
• Observer bias

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Ethnography

• Collect data by living within the cultural
  community for an extended period
• Strengths understanding cultural conflicts and
  impacts on development
• Limitations subjective, may not be generalizable

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Psychophysiological Methods

• Examine relationship between physiological
  responses and behavior
• Heart Rate compared to baseline, decrease may
  indicate interest
• EEG brain wave activity, showing arousal
  states stimulus detection
• Strengths
• Can examine behaviors in infants/young children
  before they can self-report

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Psychophysiological Methods

• Limitations?
• High degree of inference
• Change in physiology due to stimuli?

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• Table 1.3 Strengths and Limitations of Seven
  Common Research Methods

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Designs for Studying Development

• Longitudinal Design
• Same participants over time
• Can assess stability
• Can identify trends
• Can help understand individual differences

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Designs for Studying Development

• Longitudinal Design (cont)
• Limitations
• Costly and time-consuming
• Selective attrition
• Practice effects
• Cohort effects

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Designs for Studying Development

• Cross-sectional Design
• Groups of people of differing ages (although
  sometimes the same age) studied at one point in
  time
• Strengths?
• Efficient (time money), no practice effects or
  attrition
• Limitations?
• Information on individual change is not available
• Confound age and cohort effects

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• Figure 1.5 Example of a sequential design. Two
  samples of children, one born in 1998, and one
  born in 2000 are observed longitudinally between
  the ages of 6 and 12. The design permits the
  investigator to assess cohort effects by
  comparing children of the same age who were born
  in different years. In the absence of cohort
  effects, the longitudinal and cross-sectional
  comparisons in this design also permit the
  researcher to make strong statements about the
  strength and the direction of any developmental
  changes.

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Designs for Studying Development

• Microgenetic Design
• Illuminate processes that promote developmental
  change
• Repeatedly expose children ready for a
  developmental change to experiences thought to
  produce that change
• Monitor behavior as it changes

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Designs for Studying Development

• Microgenetic Design (cont)
• Strengths
• Able to see the process of change
• Limitations
• Time consuming
• Repeated observations

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Table 1.5 Strengths and Limitations of Four
Developmental Designs
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• A researcher is interested in whether there is a
  relationship between the sporting events in which
  siblings choose to engage. This researcher sent
  a survey to 500 different families and asked
  parents to write down the age of each child and
  to list in which sports each child participated.
  The researcher collected all of the surveys and
  examined whether there was a relationship between
  siblings choice of sports.
• Correlational or Experimental?
• Method?
• Observation, interview/questionnaire, clinical
  method, case study, ethnography,
  psychophysiological
• Cross-sectional, longitudinal, or sequential?
• IV and DV?

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• A researcher is interested in whether drinking
  water right before bed increases the likelihood
  that children will wet the bed at night. The
  researcher recruits 50 5-year-old children to
  participate in her study. Twenty-five children
  are given two glasses of water two hours before
  their bedtime (one glass per hour) and
  twenty-five children are prohibited from
  receiving liquids within two hours of their
  bedtime. The researcher collects information
  from the parents of the children participating
  for one week parents are telephoned and asked
  to report whether the child wet the bed each
  night.
• Correlational or Experimental?
• Method?
• Observation, interview/questionnaire, clinical
  method, case study, ethnography,
  psychophysiological
• Cross-sectional, longitudinal, or sequential?
• IV and DV?

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• A researcher was interested in how children learn
  how to settle disagreements with peers. The
  researcher talked to his 5-year-old daughter and
  asked her to describe how she interacted with her
  peers. The researcher then read a few stories to
  his daughter about children her age who got into
  disagreements and asked her what she would do in
  that situation. The researcher continued to
  interview his daughter like this for five years.
• Correlational or Experimental?
• Method?
• Observation, interview/questionnaire, clinical
  method, case study, ethnography,
  psychophysiological
• Cross-sectional, longitudinal, or sequential?
• IV and DV?

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• A researcher was interested in whether the
  construct of helplessness (e.g., low persistence,
  negative affect, negative self-evaluations) is
  similar in toddlers, preschoolers, and older
  children. The researcher recruited a group of
  2-year-olds and a group of 4-year-olds and
  brought them into a playroom setting. The
  children were videotaped playing with impossible
  puzzles and helpless behaviors were measured.
  The children were brought back two years later
  (the first group of children was then 4 and the
  second group was 6) and were given another set of
  impossible puzzles. Helpless behaviors were
  again measured.
• Correlational or Experimental?
• Method?
• Observation, interview/questionnaire, clinical
  method, case study, ethnography,
  psychophysiological
• Cross-sectional, longitudinal, or sequential?
• IV and DV?

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• A researcher is interested in whether boys or
  girls are more aggressive when playing with
  peers. The researcher goes to a playground every
  day for 5 weeks and watches children playing with
  one another. The researcher records every
  instance of aggression that he witnesses.
• Correlational or Experimental?
• Method?
• Observation, interview/questionnaire, clinical
  method, case study, ethnography,
  psychophysiological
• Cross-sectional, longitudinal, or sequential?
• IV and DV?

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• A researcher is interested in whether a mothers
  diet during pregnancy influences her babys
  cognitive ability. The researcher finds a group
  of women who were malnourished during pregnancy
  and tests their infants cognitive skills and
  finds another group of women who were not
  malnourished during pregnancy and gives the same
  test to their infants. The researcher then gives
  all of the children an IQ test when they reach
  the age of 6.
• Correlational or Experimental?
• Method?
• Observation, interview/questionnaire, clinical
  method, case study, ethnography,
  psychophysiological
• Cross-sectional, longitudinal, or sequential?
• IV and DV?

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Ethical Considerations

• Research Ethics standards of conduct to protect
  participants from harm
• Protection from harm
• Benefits to risks ratio
• Informed consent
• Confidentiality
• Deception/Debriefing/Knowledge of Results