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11.3.1 Descriptive Statistics Report


The Descriptive Statistics Report provides a summary of the
descriptive statistics that are calculated for the cluster
features.  This report is used to evaluate the effects of
trimming 2.5% (or the specified value) off the right-hand
tails of the distributions on the sample averages and
standard deviations.  Figure 11-1 illustrates a sample
Descriptive Statistics Report.

DESCRIPTIVE STATISTICS NUMBER OF OBSERVATIONS: 2000 ----------SAMPLE---------- ------TRIMMED 97.50%------ FEATURE MIN MAX AVERAGE STD DEV CV AVERAGE STD DEV CV -------- --------- --------- --------- --------- ---- --------- --------- ---- JOBMXNTA 0 6 0.2135 0.54687 2.6 0.154951 0.391913 2.5 JOBTCBTM 0.01 7115.71 16.6509 175.139 10.5 5.80658 11.0867 1.9 JOBNLR 0 334275 2327.42 12277.9 5.3 1019.77 2339.31 2.3


 Figure 11-1.  Descriptive Statistics Report

The Descriptive Statistics Report lists the following fields:

OBSERVATIONS: The number of observations used for the scaling
              procedure.  The default value is 2,000.  The
              value shown in this report differs from 2,000
              in only two cases.  The first case results when
              the population you select from the CA MICS
              database contains less than 2,000 observations.
              The second case occurs when you override the
              default value on the Workload Characterization
              screen.

FEATURE:      The feature name.  The feature names that are
              listed in the report correspond to the features
              that are specified on the Workload
              Characterization screen.

MIN:          The minimum value observed for the feature in
              the sample.

MAX:          The maximum value observed for the feature in
              the sample.

For the randomly selected SAMPLE, the following values are
calculated:

AVERAGE:      The average calculated for the feature
              observations in the sample.

STD DEV:      The standard deviation calculated for the
              feature observations in the sample.

CV:           The coefficient of variation.  The CV is
              calculated by dividing the standard deviation
              by the average.

For the trimmed SAMPLE, the percentage of the distribution
used for calculating the trimmed mean statistics is shown. In
Figure 11-1, 97.5% of the observations were included in the
calculation of the trimmed mean statistics.

AVERAGE:      The mean calculated for the feature
              observations in the trimmed sample.

STD DEV:      The standard deviation calculated for the
              feature observations in the trimmed sample.

CV:           The coefficient of variation.  The CV is
              calculated by dividing the standard deviation
              by the average.