The Preview dialog lets you see what the data will look like after the selected transformation has been applied.

See Transforming data for information about how to add a transformation to an analysis.

Option	Description
Preview after step	Lists the transformations you have added so far. Select one of these steps in the transformation chain, or the original data table to see in the preview how your data has changed with each transformation.
Data Table tab	Shows the Data Table preview tab. This tab shows what the data table looks like after each transformation.
Data Table Properties tab	Shows the Data Table Properties preview tab. This tab shows a list of all data table properties that have been defined for the data table after each transformation, and the values of these data table properties. There are two columns in the list, one with all properties and one with the corresponding values.
Column Properties tab	Shows the Column Properties preview tab. This tab shows a list of the values of all column properties for all columns in the data table after each transformation. In the list, there is a column for each property, and all columns in the data table are represented by a row.