Distributions

Cards (26)

  • What is an IQ test primarily composed of?
    A series of logic questions
  • What does an IQ score measure?
    It measures intelligence
  • What is the average IQ score?
    100
  • What does a higher IQ score indicate?
    Greater intelligence
  • How do most people's IQ scores relate to the average?
    They score close to 100
  • What shape does the distribution of IQ scores form on a graph?
    A bell shape
  • What is the term for the common distribution of data that forms a bell shape?
    Normal distribution
  • What are the characteristics of a normal distribution?
    • Symmetrical curve
    • Mean, median, and mode are equal
    • Sides do not touch the x-axis
  • What does the y-axis represent in a histogram?
    Frequency of scores
  • What does the x-axis represent in a histogram?
    Value of the scores
  • What does the mode represent in a normal distribution?
    The most common score
  • How is the median defined in a normal distribution?
    It is the middle score
  • What does the mean represent in a normal distribution?
    The average score
  • How does the symmetry of the curve affect the mean, median, and mode?
    They are all at the center
  • What percentage of scores falls within one standard deviation of the mean?
    68%
  • What percentage of scores falls within two standard deviations of the mean?
    95%
  • What percentage of scores falls within three standard deviations of the mean?
    99.7%
  • If someone scores 130 on an IQ test, what does this indicate about their position in the population?
    They are in the top 2.5%
  • How is abnormality defined in terms of IQ scores?
    As statistically infrequent scores
  • What are the characteristics of skew distributions?
    • Scores shifted to one side
    • Long tail either right (positive) or left (negative)
    • Not symmetrical
  • What indicates a positive skew in a distribution?
    The tail points to the right
  • What indicates a negative skew in a distribution?
    The tail points to the left
  • How can a test's difficulty affect its score distribution?
    Easy tests lead to negative skew
  • What happens to the mean in a skewed distribution?
    It is pulled towards the tail
  • Where is the median located in a skewed distribution?
    Between the mode and the mean
  • What are the measures of central tendency in a distribution?
    • Mode: Most frequent score
    • Mean: Average score
    • Median: Middle score