Research Ch. 16

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Research Ch. 16
2015-11-03 17:17:39

Research Ch. 16 Descriptive Statistics
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  1. What are two examples of description statistics?
    • 1. Averages
    • 2. Percentages
  2. A __________is a descriptive statistic calculated from population data
  3. The 4 levels of measurement are
    • 1. nominal
    • 2. ordinal
    • 3. interval
    • 4. ratio
  4. _________ is the lowest level of measurement and involves assigning #'s to classify characteristics into categories. The numbers do not have mathematical meaning
  5. Give 3 examples of nominal measurements.
    • 1. gender
    • 2. blood type
    • 3. marital status
  6. The #'s assigned in nominal measurement a. have or b. do not have quantitative meaning
    b. do not have
  7. Nominal measurements must be classifiable into 1 and only 1 category. Thus they must be___________ and __________.
    For example, 1=married, 2=separated or divorced, 3=widowed.
    • mutually exclusive
    • collectively exhaustive
  8. _________ measurement goes beyond categorization and involves sorting people based on their relative ranking on an attribute
  9. In an ordinal measurement, we only know the ________ ranking.
    Examples of this type of measurement include: ____ _____
    • relative
    • frequency counts
    • percentages
  10. ________ measurement occurs when researchers can specify rank ordering on an attribute and can assume equivalent distance between them
  11. An example of an interval measurement is____
    Farenheit Temp scale
  12. Interval measurements are more informative than ordinal ones, but they do not convey _______ magnitudes, because there is no rational zero point.
  13. Example of interval measurements is______
    psychological and educational testing
  14. In _________ measurement we can meaningfullly calculate an average which expands our analytic possibilities
  15. ________ measurement is considered the highest level and provides information about ordering on the critical attribute, the intervals between objects, AND the absolute magnitude of the attribute because they have  a rational, meaningful zero.
  16. An example of a ratio measure is _____
  17. A _________ distribution is a systematic arrangment of values from the lowest to highest, together with a count of the number of times each value was obtained
  18. Frequency distributions consist of 2 values;
    _____ the observed value
    ______ the frequency of cases at each value
    • the x's
    • the f's
  19. Sum of f's =_____
    N (total sample size)
  20. Examples of graphs that display interval and ratio level data
    Histograms and Frequency polygons
  21. Frequency polygons can assume many shapes. A _______ distribution has two equal halves and a _________ distrubution has a peak that is off center and a tail longer on one side than the other.
    • symmetric
    • skewed
  22. When the tail of a skewed distribution points to the right, the distribution is _________.
    positively skewed
  23. When the tail of the distribtion points to the left, the distribution is _________
    negatively skewed
  24. Age at death is an example of a ________ skewed attribute.
  25. A ________ distribution has a symmetrical peak.
    Normal (Bell Curve or Gaussian distribution)
  26. The 3 measures of central tendency is are:
    ____, ______ and ________
    • mean
    • median
    • mode
  27. The _____ is the most frequently occurring score in a central distribution
  28. The ________is the point in a distribution above which and below which 50 % of cases fall.
  29. Modes are a quick way to determine a ________ score, but are rather _____
    • Popular
    • Unstable
  30. The ______ is used primarily to describe typical values for nominal-level measures.
  31. The value that divides the cases exactly in half is the ________ for the set of numbers.
  32. The ______ is the sum of all scores, divided by the number of scores.
    Mean (M) or X (with line over it)
  33. Another name for the mean is the ______.
  34. The ______ is the most widely used measure of central tendency.  It is the most ______because if repeated samples were drawn from a population, means would fluctuate less than modes or medians.
    • Mean
    • Stable
  35. If the goal is to understand what is "typical" in a sample, the _______ may be the best measure of central tendency. As in a the income level of a group.
  36. When a distribution is symmetric and unimodal, the three indexes of central tendency _______
  37. In a skewed distribution, the mean , median and mode will _________
  38. In a skewed distribution the mean always pulls in the direction of the long ________
  39. The ________ is most suited for nominal measures.
  40. Both the ____ and ____ are suitable for ordinal measures.

    (measures of central tendency)
    • mode
    • median
  41. The ________ is appropriate for interval and ration measures.
    ( a measure of central tendency)
  42. ______ is the measure of how spread out or dispersed the data are.
  43. The _______ is the highest score minus the lowest score.
  44. The range is ________ because it is based on only two numbers.
  45. _______ is a measure of variability used for interval or ratio-level data. It indicates the average amount of deviation of values from the mean and is calculated in every score.
    Standard Deviation
  46. A _______ score is the difference between an individual score and the mean.
    • Deviation
    • x=X- mean
  47. If a person weighed 150 lbs and the sample mean were 140. The person's deviation score would be______
    + 10.
  48. Deviations above the mean always ______ deviations below the mean, so that the net sum of them is 0.
  49. _______ is the value of the standard deviation before a square root has been taken, and it is a related index of variability.
  50. In a normal or near normal distribution there are roughly ______ SD's above and below the mean.
  51. The ______ is a useful variability index for describing a distribution and interpreting individual scores.
    Standard Deviation
  52. Like the mean, the SD is a _______ estimate of a parameter and is the preferred index of a distribution's __________
    • stable
    • variability.