Item Analysis
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Stat > Multivariate > Item Analysis

Use to assess how reliably multiple items in a survey or test measure the same construct. Several types of statistics are presented to help you determine both the overall and item-by-item reliability. Cronbach's alpha measures the degree of internal consistency for all included items. The inter-item correlation matrix displays the strength of the relationship between every pair of items. Omitted item statistics assess whether removing an item from the analysis improves the internal consistency.

Dialog box items

Variables: Enter two or more columns containing the items to analyze.

Standardize variables: Check to standardize your data. Standardize if your items are measured on different scales and you want to give equal weight to each item. The standardized values are used to calculate Cronbach's alpha and omitted-variable correlations. These values are only used in calculating statistics and are not stored in the worksheet.

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