T-Test for Dependent Samples

See the t-Test for Dependent Samples Overview.

Variables

1. Click this button to display a variable selection dialog box
2. Select two lists of variables to be analyzed. Each variable in the first list is compared with each variable in the second list.

   Summary

Click this button to compute the t-tests for dependent samples and display the results in a spreadsheet.

The detail and formatting of the results depends on your selections on the Advanced tab.

Cancel

Click this button to close the dialog box without performing an analysis and return to the Basic Statistics and Tables dialog box.

Options

Click this button to display the Options menu.

By Group

Click this button to display the By Group specification dialog box.

Select Cases

Click this button to display the Analysis/Graph Case Selection Conditions dialog box, which contains options to create conditions for which cases will be included (or excluded) in the current analysis.

More information is available in the case selection conditions overview and syntax summary.

W

Click the W (weight) button to display the Analysis/Graph Case Weights dialog box.

Use these options to adjust the contribution of individual cases to the outcome of the current analysis by weighting those cases in proportion to the values of a selected variable.

Wghtd momnts

Select the Wghtd momnts (weighted moments) check box to specify that each observation contributes the weighting variable's value for that observation.

• The weight values need not be integers.
• This module can use fractional case weights in most computations (Some other modules 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 option above.

  DF = W-1 / N-1

When the Wghtd momnts check box is selected, some statistics related to the moments ( for example,  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 are always based on the weighted values of the respective observations. However, in computations requiring the degrees of freedom (such as, 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 Wghtd momnts check box is selected, several graphics options are not 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 are included in the analyses for the respective variables (resulting possibly in unequal valid N per variable).