Beside each item in the results list is a check box (see illustration). These boxes are initially unchecked.
Check the boxes by the side of items you are interested in, and click on the Improve button. The search will be automatically modified to return more items similar to those you have checked.
Top Terms allows you to choose words that empower has identified as being important to your query. After you have performed an initial search, a short list of words (shown in their stemmed form) is presented at the top of the results screen:
Select the words that you feel are most relevant to your interests, and click on the search button.
Note that you can increase the power of the Top Terms feature by using it in conjunction with the Improve feature.
Each time you click on the Improve button, the list of words in the Top Terms box (example shown above) will change.