PSY571_Ch2_Glossary

  1. Frequency Distribution
    A tabulation of the number of occurrences of each score value. An organized tabulation of scores or categories and the number of times they appear in a given population or sample.
  2. Relative Frequency
    The proportion of observations in the distribution at that score value. The number of occurrences of a particular score value in relationship to the total score value.
  3. Relative Frequency Distribution
    A listing of the relative frequencies of each score value.
  4. Cumulative Frequency Distribution
    A tabulation of the frequency of all measurements at or smaller than a given score value. Used to help calculate percentiles.
  5. Cumulative Relative Frequency Distribution
    A tabulation of the relative frequencies of all measurements at or below a given score value. This is used to directly calculate percentile ranks.
  6. Class Interval
    A range of score values. A group of score values that is used to help summarize data that contains many different score values.
  7. Grouped Frequency Distribution
    A tabulation of the number of measurements in each class interval or the number of occurrences of scores that fall in each class interval.
  8. Abscissa
    x-axis or the horizontal line. Often marked in units of the variable being measured.
  9. Ordinate
    y-axis or vertical line. Often marked in units of frequency or relative frequency.
  10. Relative Frequency Histogram
    A type of frequency distribution graph that uses the heights of bars to represent relative frequencies of score values or class intervals.
  11. Discrete variable
    A type of variable in which no values can exist between two adjacent scores or values.
  12. Continuous variable
    A type of variable in which an infinite number of values can exist between any two scores.
  13. Symmetrical Distribution
    A type of distribution where if it is divided in half, the two halves are mirror images of each other.
  14. Positively skewed distribution
    A type of distribution in which the tail of the graph points towards the right hand side or the side with the higher scores.
  15. Negatively skewed distributions
    A type of distribution in which the tail of the graph points to the left hand side or the side with the lower values of a score.
  16. Unimodal, Bimodal, Multimodal Distributions
    Distribution with one peak or mode. Distribution with two peaks or modes. Distribution with more than two peaks or modes.
  17. Central Tendency of a Distribution
    A score value near the center of the distribution; it is supposed to be a typical or representative score value. Often measured as the mean, median, or mode.
  18. Variability
    The degree to which the measurements in a distribution differ from one another. A measurement of how clustered or scattered the scores are in a given distribution.
  19. Percentile Rank
    The percent of measurements in the distributions below that score value.
  20. Percentiles
    The score value with P% of the measurements in the distribution. Not sure if this refers to the actual score or the percentage still.
Author
darwinguevarra
ID
62549
Card Set
PSY571_Ch2_Glossary
Description
Ch. 2: Frequency Distributions and Percentiles
Updated