Methods- Chapter 1

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Methods- Chapter 1
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I. Why is Psychology a science?

• Deals with experiments and scientific method.

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A. Human Tendencies

• 1. Hindsight Bias tendency to believe, after
  learning an outcome, that one would have foreseen
  it.
• 2. Overconfidence to overestimate the accuracy
  of ones beliefs and judgments.

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II. Methods of Research

• A. Descriptive Research
• 1. Case Study one person is studied in depth in
  the hope of revealing universal principles.
• 2. Survey acquiring the self-reported attitudes
  or behaviors of people, usually by questioning a
  representative, random sample of them

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• 3. Naturalistic Observation observing
  recording behavior in naturally occurring
  situations. Describes, not explains
• Methods 1-3 can only show correlations. (meaning
  one factor predicts the other, but does not
  necessarily cause it)

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• B. Correlational Research
• 1. Positive Correlations When one variable goes
  up the other goes up. When one variable goes down
  the other variable goes down.
• 2. Negative Correlations When one variable goes
  up the other goes down.
• 3. Correlation coefficient Statistical measure
  of a relationship. (how well one predicts the
  other)

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• 4. Scatter plotsgraph showing correlation
• 5. Correlation Causationcorrelation does not
  prove cause and effect
• 6. Illusory correlations When we believe there
  is a relationship between two things, we are
  likely to notice and recall instances that
  confirm our belief

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Example of Illusory Correlation
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Warm-up

• Give an example, not used in class, of
• 1. a positive correlation
• 2. a negative correlation
• 3. an illusory correlation

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• C. Experimental Research- Proves Cause and Effect

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• When doing an experiment you must first form a
  hypothesis (testable prediction). If proven
  correct over and over, the hypothesis may lead to
  a theory (idea)
• Next you must randomly select a sample from the
  population.
• Second you must form an experimental group, which
  gets the independent variable, and a control
  group which does not but will get a placebo in a
  drug study

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• The independent variable is the factor that you
  are testing.
• A placebo is a sugar pill.
• You must make sure to use random assignment when
  choosing who goes in the experimental and the
  control group.

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• Single Blind Study participant doesnt know who
  is in the experimental vs. control group.
• Double Blind Study participant and experimenter
  dont know who is in the experimental vs. control
  group.
• After the experiment you should record your
  results.
• You should always replicate your experiment.
• Your measurable results are known as the
  dependent variable.

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• Tip
• If you phrase a hypothesis as I am looking for
  the effect of _________ on _______ the first
  blank is always the IV and the second is always
  the DV.
• What are the IV and DV in the following study
• Eating chicken makes you grow taller. What
  operational def. can you use?

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• Controls
• Controls on an experiment would include
• 1. Random selection
• 2. Random assignment
• 3. Double-blind study
• 4. good operational definition of variables
• 5. Replication

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My Teacher is Mean!

•  Jimmy is a little upset about his grade for his
  science fair project. He worked on it for an
  entire month. What did he do wrong?
• Jimmy did a science fair project studying the
  effect of eating fish on intelligence. He began
  his study by recruiting several of his friends to
  eat at least three servings of fish sticks every
  day for one month. At the end of the month Jimmy
  gave them all a test he printed off the internet
  about World War II. They scored really well.
  Jimmy concluded that fish does indeed increase
  intelligence. He even dressed up like a giant
  fish when he gave his presentation

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• There are lies, damn lies, and then there are
  statistics.

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III. Statistics

• Descriptive Statistics
• 1. Measures of Central Tendency a way to
  summarize data using mean, median, mode.
• A. Mean average score.

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• B. Median the middle score in a distribution
  half the scores are above it and half are below
  it.
• C. Mode the most frequently occurring scores in
  a distribution.

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2. Distributions

• A. Normal when the mean, median, and mode are
  identical-creates symmetrical distribution
• B. Positively skewed when a score is much higher
  than the rest of the scores, making the mean
  higher.
• C. Negatively skewed when a score is much lower
  than the rest of the scores, making the mean
  lower.

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• D. Standard deviation determines whether
  information is packed together or dispersed.
• E. Variance how similar or diverse scores are.
• variance standard deviation squared
• Example basketball player scored between 13 17
  pts in each of her first 10 games. Knowing this,
  we would be more confident that she would score
  near 15 points her next game than if her scores
  had varied form 5 to 25

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3. Use of statistics in Psychology

• A. The Flynn effect with every generation,
  standardized test scores are getting higher.

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• Inferential Statistics
• A. Statistical significance how important are
  the findings
• B. P Value the likelihood that your results were
  by chance
• C. Type I error when your hypothesis is wrong
  but seems to be proven right (false-positive)
• Type II error when your hypothesis is right but
  seems to be proven wrong (false-negative)

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IV. Ethics

• A. With humans cannot hurt a human knowingly.
• B. With animals not very many laws protecting
  animals in the U.S.