Cronbach Alpha

Computes the Cronbach Alpha for all numerical columns based on their variance. Cronbach's Alpha compares the variance of the individual columns with the variance of the sum of all columns. It typically serves as an estimate of the reliability of a psychometric test. Cronbach Alpha is known as an internal consistency estimate of reliability of test scores since it will generally increase as the intercorrelations among test items increase. The theoretical value of alpha varies from zero to 1. However, depending on the estimation procedure used, estimates of alpha can take on any value less than or equal to 1. If Missing Values are encountered the node will fail.

Options

Manual Selection

Include
This list contains the names of those columns in the input table to be included in the Cronbach Value.
Exclude
This list contains the names of those columns in the input table to be left out of the calculation.
Filter
Use one of these fields to filter either the Include or Exclude list for certain column names or name substrings.
Buttons
Use these buttons to move columns between the Include and Exclude list. Single-arrow buttons will move all selected columns. Double-arrow buttons will move all columns (filtering is taken into account).
Enforce Exclusion
Select this option to enforce the current exclusion list to stay the same even if the input table specification changes. If some of the excluded columns are not available anymore, a warning is displayed. (New columns will automatically be added to the inclusion list.)
Enforce Inclusion
Select this option to enforce the current inclusion list to stay the same even if the input table specification changes. If some of the included columns are not available anymore, a warning is displayed. (New columns will automatically be added to the exclusion list.)

Wildcard/Regex Selection

Wildcard/Regex Selection
Type a search pattern which matches columns to move into the Include or Exclude list. Which list is used can be specified. You can use either Wildcards ('?' matching any character, '*' matching a sequence of any characters) or Regex. You can specify whether your pattern should be case sensitive.

Input Ports

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Numeric input data to evaluate

Output Ports

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The Cronbach Alpha in a data table with one row/column

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