# Descriptive Statistics - Advanced tab

In the Descriptive Statistics dialog box, select the Advanced tab  to access options to specify the type of descriptive statistics to calculate for each variable. Note that the selections made here determine the statistics calculated when the Summary: Statistics button is clicked on this tab or the Quick tab.

Summary: Statistics. Click this button to produce a spreadsheet with the descriptive statistics for the selected variables. You can request specific descriptive statistics using the options described below.

G1. Click this button to produce a compound graph for each selected variable consisting of a histogram, normal probability plot, box plot, and descriptive statistics. This is a quick way to graphically explore variables.

G2. Click this button to produce a compound graph for each selected variable consisting of a histogram, horizontal box plot, and descriptive statistics. This compound graph has more descriptive statistics such as variance, skewness and confidence for mean.

Compute statistics. The options selected in these fields determine which statistics are computed when you click the Summary: Statistics button on this tab or the Quick tab. Refer to the Introductory Overview for a discussion of the most common descriptive statistics and their interpretation.

Location, valid N. Select the check box next to the statistics you want computed. The statistics in this group box are used to estimate the location of the distribution as well as to determine the number of valid cases for each selected variable (Valid N and Percent of Valid Observation). You can estimate a variety of location statistics including Mean, Sum, Median, Mode, Geometric mean, and Harmonic mean.

Variation, moments. Select the check box next to the statistics you want to compute. The statistics in this group box are used to estimate the variation for the variable as well as a variety of its moments and their standard errors. You can estimate the Standard Deviation, CI for Sample SD Interval, Coefficient of Variation, Variance, Standard error of the mean, and Confidence limits for means. When computing confidence levels, you must specify the confidence Interval via the edit box. Refer to the Introductory Overview for a basic discussion of confidence limits. You can also calculate the Skewness and its Standard error as well as the Kurtosis and its Standard error.

Percentiles, ranges. Select the check box next to the statistics you want to compute. The options in this group box are used to estimate a variety of percentiles and ranges for each variable. You can select Minimum & maximum values, Lower & upper quartiles, Percentile boundaries (see note below), Range, and Quartile range.

Note: Percentile boundaries. Use the Boundaries option button (located under the Percentile boundaries check box) to enter which percentiles you want calculated by editing the percentages in the adjacent edit field (the default boundaries are the deciles); use the Intervals option button to divide the percentiles evenly among the interval number in the adjacent edit field (the default interval is 10, which would also give the deciles of the data).

Note: Computation of median and quartiles (25th, 50th, and 75th percentiles). When the distribution of values cannot be exactly divided into halves and quartiles, there are different ways to compute the respective median and quartile values (and percentiles). The specific method of computation for those values can be configured system-wide via the Computations of percentiles option in the Options dialog box - Analyses/Graphs: Limits tab.

Select all stats. Click this button to select all the statistics.

Reset. Click this button to clear all but the default statistics. The default statistics are: Valid N, Mean, Standard Deviation, and Minimum & Maximum.

Save settings as default. Click this button to save the current selection of default statistics as the default for future analyses. To reset the system defaults, click the Reset button.