Myers

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Myers PSYCHOLOGY (7th Ed)

• Chapter 1
• Thinking Critically with Psychological Science
• James A. McCubbin, PhD
• Clemson University
• Worth Publishers

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The Need for Psychological Science

• Psychologists, like all scientists, use the
  scientific method to construct theories that
  organize observations and imply testable
  hypotheses

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The Need for Psychological Science

• Hindsight Bias
• we tend to believe, after learning an outcome,
  that we would have foreseen it
• the I-knew-it-all-along phenomenon
• Overconfidence
• we tend to think we know more than we do

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The Need for Psychological Science

• Critical Thinking
• thinking that does not blindly accept arguments
  and conclusions
• examines assumptions
• discerns hidden values
• evaluates evidence

The Amazing Randi--Skeptic
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The Need for Psychological Science

• Theory
• an explanation using an integrated set of
  principles that organizes and predicts
  observations
• Hypothesis
• a testable prediction
• often implied by a theory

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The Need for Psychological Science
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The Need for Psychological Science

• Operational Definition
• a statement of procedures (operations) used to
  define research variables
• Example-
• intelligence may be operationally defined as what
  an intelligence test measures

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The Need for Psychological Science

• Replication
• repeating the essence of a research study to see
  whether the basic finding generalizes to other
  participants and circumstances
• usually with different participants in different
  situations

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Description

• Psychologists describe behavior using case
  studies, surveys, and naturalistic observation

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Description

• Case Study
• Psychologists study one or more individuals in
  great depth in the hope of revealing things true
  of us all

Is language uniquely human?
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Description

• Survey
• technique for ascertaining the self-reported
  attitudes or behaviors of people
• usually by questioning a representative, random
  sample of people
• Random Sample
• a sample that fairly represents a population
  because each member has an equal chance of
  inclusion

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Description

• False Consensus Effect
• tendency to overestimate the extent to which
  others share our beliefs and behaviors
• Population
• all the cases in a group, from which samples may
  be drawn for a study

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Description
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Description

• Naturalistic Observation
• observing and recording behavior in naturally
  occurring situations without trying to manipulate
  and control the situation

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Correlation

• Correlation Coefficient
• a statistical measure of the extent to which two
  factors vary together, and thus how well either
  factor predicts the other

Indicates direction of relationship (positive or
negative)
Correlation coefficient
r .37
Indicates strength of relationship (0.00 to 1.00)
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Correlation

• Scatterplot
• a graphed cluster of dots, each of which
  represents the values of two variables
• the slope of the points suggests the direction of
  the relationship
• the amount of scatter suggests the strength of
  the correlation
• little scatter indicates high correlation
• also called a scattergram or scatter diagram

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Correlation
Scatterplots, showing patterns of correlations
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Experimentation

• Experiment
• an investigator manipulates one or more factors
  (independent variables) to observe their effect
  on some behavior or mental process (the dependent
  variable)
• by random assignment of participants the
  experiment controls other relevant factors

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Experimentation

• Placebo
• an inert substance or condition that may be
  administered instead of a presumed active agent,
  such as a drug, to see if it triggers the effects
  believed to characterize the active agent
• Double-blind Procedure
• both the research participants and the research
  staff are ignorant (blind) about whether the
  research participants have received the treatment
  or a placebo
• commonly used in drug-evaluation studies

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Experimentation

• Experimental Condition
• the condition of an experiment that exposes
  participants to the treatment, that is, to one
  version of the independent variable
• Control Condition
• the condition of an experiment that contrasts
  with the experimental treatment
• serves as a comparison for evaluating the effect
  of the treatment

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Experimentation

• Random Assignment
• assigning participants to experimental and
  control conditions by chance
• minimizes pre-existing differences between those
  assigned to the different groups

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Experimentation

• Independent Variable
• the experimental factor that is manipulated
• the variable whose effect is being studied
• Dependent Variable
• the experimental factor that may change in
  response to manipulations of the independent
  variable
• in psychology it is usually a behavior or mental
  process

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Experimentation
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Statistical Reasoning

• Mode
• the most frequently occurring score in a
  distribution
• Mean
• the arithmetic average of a distribution
• obtained by adding the scores and then dividing
  by the number of scores
• Median
• the middle score in a distribution
• half the scores are above it and half are below it

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Statistical Reasoning

• A Skewed Distribution

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Statistical Reasoning

• Range
• the difference between the highest and lowest
  scores in a distribution
• Standard Deviation
• a computed measure of how much scores vary around
  the mean
• Statistical Significance
• a statistical statement of how likely it is that
  an obtained result occurred by chance

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Frequently Asked Questions about Psychology

• Can laboratory experiments illuminate everyday
  life?

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Frequently Asked Questions about Psychology

• Does behavior depend on ones culture?
• Culture--the enduring behaviors, ideas,
  attitudes, and traditions shared by a large group
  of people and transmitted from one generation to
  the next

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Frequently Asked Questions about Psychology

• Does behavior vary with gender?

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Frequently Asked Questions about Psychology

• Why do psychologists study animals?
• Is it ethical to experiment on animals?
• Is it ethical to experiment on people?

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Frequently Asked Questions about Psychology

• Is psychology free of value judgments?

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Frequently Asked Questions about Psychology

• Is psychology potentially dangerous?