Workspace Node: Descriptive Statistics - Specifications - Quick Tab

The Descriptive Statistics workspace node can be accessed from the Feature Finder, ribbon bar, or Node Browser. The Quick tab of the specifications dialog box is displayed by default when you double-click the node.

See also, Descriptive Statistics Overviews.

Variables. Click this button to display a standard variable selection dialog box, in which you select the variables for the analysis.

Weighted moments. Select this check box to specify that each observation contributes the weighting variable's value for that observation. The weight values need not be integers. This node can use fractional case weights in most computations. Some other nodes use case weights as integer case multipliers or frequency values. This option is available only after you have defined a weight variable via the W (weight) option located at the bottom of the dialog box.

DF = W-1 / N-1. When the Weighted moments check box is selected, some statistics related to the moments (e.g., standard deviations and variances, skewness, kurtosis) can be based on the sum of the weight values for the weighting variable (W-1), or on the number of (unweighted) observations (N-1). The sums (and means), and sums of squares and cross products will always be based on the weighted values of the respective observations. However, in computations requiring the degrees of freedom (e.g., standard deviation, t-test, etc.), the value for the degrees of freedom can either be computed as the sum of the weight values minus one, or as the number of observations minus one.

Moment statistics (except for the mean) are based on the sum of the weight values for the weighting variable when the W-1 option button is selected, and are based on the number of (unweighted) observations when the N-1 option button is selected. When the Weighted moments check box is selected, several graphics options will not be available. For more information on options for using integer case weights, see Selecting a weighting variable.

MD Deletion. If Casewise deletion of missing data is selected, Statistica ignores all cases that have missing data for any of the variables selected in the list. If Pairwise deletion of missing data is selected, all valid data points will be included in the analyses for the respective variables (resulting possibly in unequal valid N per variable).

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.

See also, Results - Quick tab, Results - Advanced tab, Results - Robust tab, Results - Normality tab, Results - Prob. & Scatterplots tab, Results - Options tab, Downstream tab, and Home tab.