Search results: refine by subject
Refine by subject allows you to narrow your search to a particular subject classification.
You can either choose one of the six top-level subjects, or click the + symbol to drill down. When you find the subject you're looking for, click on it to add it to your search terms. Once you've selected, your results list will change to include only items with that classification, and only that term will be available in the Refine by box on the right.
To clear and change subject, click the x next to the label in the SEARCH RESULTS (or BROWSE) box, and use the subject tree to reselect.