Lecture 2 The Science of Psychology

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Lecture 2The Science of Psychology
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Todays Outline

• Critical Thinking Science
• Psychological Methods
• Types of data
• Self report
• Observation
• Research Design
• Archival
• Correlational
• Longitudinal
• Experimental

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Methods of PsychologyScientific Method

• Science starts with an attitude and a desire for
  the truth
• Systematic empirical study of phenomena
• __________ keep the bias out, include all data
  and information even if it doesnt fit
• __________ based on observable events
• __________ must be measurable

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Short Video

• What was the study?
• Did people believe it?
• Whats a placebo?
• Why do placebos work?

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Problems with Common Sense

• People see some parts of the world and miss
  others
• due to preconceptions, ability, attention, etc.)
• People notice those things that fit
  preconceptions
• People often believe to be true whatever feels
  good

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The Scientific Method

• To develop theories about the world and to test
  those theories using observations
• Theory An explanation
• Scientific theory is backed by data
• The scientific process
• Is self correcting (theories are tested, then
  revised, then tested)
• Theories are _________
• The process is objective and public

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The Science of Psychology

• Separating anecdotes, folk wisdom and advice from
  data and conclusions!
• Scientific Research is
• Formulating _______________
• Testing __________ using the scientific method
• Interpreting the results
• Communicating the results --- realistically

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The goals of science

• Description What happens?
• Prediction When does it happen?
• Explanation Why does it happen?
• Theory
• Causal Inferences
• Intervention/Application What could be done to
  help?
• These all build on each other

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Self Report

• Self-report methods ask participants to tell
  you
• Interviews
• Questionnaires
• Daily diary methods

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Observational Data

• Observational Data
• Observations in natural settings
• Laboratory-based observation

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Research Designs

• Archival digging through the vaults
• Correlational research when one goes up, what
  happens to the other?
• Longitudinal research how do things relate over
  time?
• Experimental research if one is changed, what
  happens to the other?

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Archival Research

• Researchers examine existing data that may or may
  not have been intended for research
• Harker and Keltner (2001) used yearbook pictures
  to predict marital outcomes 30 years later

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Archival Results

• Smiling at age 20 predicted

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Correlational Research

• Assess the naturally occurring associations among
  two variables
• Positive correlation
• rewards are positively associated with
  satisfaction
• Negative correlation
• conflicts are negatively associated with
  satisfaction

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Correlational research
The statistical concept of a correlation
coefficient (r)
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Correlation does not imply causation!

• Three possible interpretations of any correlation

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Pros and Cons of Correlational Research
(descriptive)

• Advantages
• Disadvantages

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Longitudinal Research

• Data collected at 2 or more time points
• Associations among variables across time
• How are feelings of love across time associated
  with divorce?

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Longitudinal Research

• Associations among variables within a day
• How does a partners behavior during the day
  influence feelings of commitment at night?

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Pros and Cons of Longitudinal

• Advantages
• Disadvantages

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Experimental Research

• Manipulate one variable to see if it causes
  changes in another variable.
• Does arousal lead to greater liking?

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Testing the WHATs and WHYs

• 11 correspondence
• If you pour x into y, you know x caused the
  explosion
• If you pour x and z into y, you dont know what
  caused the explosion
• Random Assignment
• In large enough samples, characteristics will be
  equally distributed

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Experimental Video Games Violence

• What is an independent variable?
• What is a dependent variable?
• What is the point of experiments?
• What is random assignment?
• How are differences controlled?

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Pros and Cons of Experimental

• Advantages
• Disadvantages