test 3 Flashcards
quantitative analysis
the numerical representation and manipulation of observations for the purpose of describing and explaining the phenomena that those observations reflect.
codebook
the document used in data processing and analysis that tells the location of different data items in a data file. Typically, the codebook identifies the locations of data items and the meaning of the codes used to represent different attributes of variables.
univariate analysis
the analysis of a single variable, for purposes of description. Frequency distributions, averages, and measures of dispersion would be examples of univariate analysis, as distinguished from bivariate and multivariate analysis.
frequency distribution
A description of the number of times the various attributes of a variable are observed in a sample. The report that 53 percent of a sample were men and 47 percent were women would be a simple example of a frequency distribution.
average
an ambiguous term generally suggesting typical or normal- a central tendency. The mean, median, and mode are specific examples of mathematical averages.
mean
an average computed by summing the values of several observations and dividing by the number of observations. If you now have a grade point average of 4.0 based on 10 courses, and you get an F in this course, your new grade point (mean) average will be 3.6.
mode
an average representing the most frequently observed value or attribute. If a sample contains 1,000 protestants, 275 catholics, and 33 Jews, Protestant is the modal category
median
An average representing the value of the ‘‘middle’’ case in a rank- ordered set of observations. If the ages of five men are 16,17, 20, 54, and 88, the median would be 20. ( The mean would be 39.)
dispersion
the distribution of values around some central value, such as an average. The range is a simple example of a measure of dispersion. Thus, we may report that the mean age of a group is 37.9, and the range is from 12 to 89.
standard deviation
a measure of dispersion around the mean, calculated so that approximately 68 percent of the cases will lie within plus or minus one standard deviation from the mean, 95 percent will lie within plus or minus two standard deviations, and 99.9 percent will lie within three standard deviatons. Thus for example, if the meanage in a group is 3 and the standard deviation is 10, then 68 percent have ages between 20 and 40. The smaller the standard deviation, the more tightly the values are clustered around the mean; if the standard deviation is high, the values are widely spread out.