It is very helpful to preview the results of your mapping as you go along. To do this, click on the preview
button at the top of the mapping editor window. The preview options will appear on the right-hand side of the screen. Use this to select the previews that you would like to see. In this example we have mapped the input schema to the CARARE schema, and the preview options selected are the original item, the mapped item (CARARE format) and the EDM item (transformed from CARARE to EDM using the inbuilt mapping provided by CARARE).
Preview options
You will notice that the preview area provides a list of the records in the dataset. Click on one of the items to preview it.
The preview pane will open and allow you to
  • compare the input item with the mapped item
  • see whether the mapped item(s) are valid according to the rules of the target schema.
Note: It is useful to preview several records. Across a dataset, some records may not include data in all the elements. This means that a mapping can produce both valid and invalid records. Previewing the results allows you to assess whether tweaking the mapping will produce better results across the whole dataset.
Previewing the results of a mapping
The example in below shows that the mapping has produced valid records according to the rules of the CARARE schema. However, switching tabs to view the EDM records (produced automatically by the mapping between the CARARE and EDM schemas) shows that some data is missing.
Showing the validation report
Clicking on Show/hide report shows the validation errors. In this case validation has failed because the Europeana rights element has not been completed in the CARARE mapping, and the description lacks a language attribute. These errors can be corrected by returning to the mapping and completing the relevant elements.
Once you have completed previewing the records and made a note of any mistakes, close the preview panel. You can then return to the mapping editor and adjust your mapping until you are satisfied with the results.