Workspace Node: Descriptive Statistics - Results - Options Tab

Note that options selected here will only affect the calculations of descriptive statistics.

Select this check box to display the long variable names (if any, see Variable Specs Editor) along with the short names in the first column of the results spreadsheets. If no long variable names have been specified for any of the selected variables, the setting of this check box will have no effect.

Select this check box to use extended precision calculations in your descriptive statistics. Statistica employs proprietary extended precision algorithms in order to minimize round-off error in the computations. This option should be selected if the variables in the analysis show extremely small relative variances (variance divided by the mean), for example, if all values for a variable range between 10000.000001 and 10000.000002 (note that there is a difference between small variance and small relative variance; e.g., the relative variance of values in the range of .0000000000000001 to .0000000000000002 is not small). For extremely large data files with many thousands of cases, the computations may be somewhat slower when this check box is set.

Options for Box-Whisker plots. Use the check boxes in this group box to specify which type of box-whisker plot to produce. If more than one check box is selected (e.g., Median/Quartiles/Range and Mean/SD/1.96*SD), more than one plot will be produced, one for each type of box-whisker plot. These options apply to the regular Box & whisker plot for all variables on the

Results

- Quick tab.

This box plot describes the central tendency of the variable in terms of the median of the values (represented by the smallest box in the plot). The spread (variability) in the variable values is represented in this plot by the quartiles (the 25th and 75th percentiles, larger box in the plot) and the minimum and maximum values of the variable (the "whiskers" in the plot).

Here, the smallest box in the plot represents the mean (central tendency) of the variable, while the dispersion (variability) is represented by ± 1 times the standard error (large box) and ± 1 times the standard deviation about the mean ("whiskers").

This plot will show the mean (small box in the plot) of the variable surrounded by a larger box (± 1 times the standard deviation). If the distribution is normal, then the "whiskers" in this plot represent a "95% confidence interval" defined as the variable mean ± 1.96 times the variable standard deviation.

This plot will show the mean (small box in the plot) of the variable surrounded by a larger box. However, in this plot, the larger box represents ± 1 times the standard error. If the distribution is normal, the "whiskers" in this plot represent a "95% confidence interval" defined as the variable mean ± 1.96 times the variable standard error.

Options / C / W. See Common Options.

OK. Click the OK button to accept all the specifications made in the dialog box and to close it. The analysis results will be placed in the Reporting Documents node after running (updating) the project.