What do the circles mean in the search results dialogue box?
From full circle to empty circle, they rank documents from highest to lowest likelihood of containing relevant information. The relevance ranking indicates how frequently the search word appears in the document, both in absolute terms and relative to the number of other words in the document. When you use an OR between two words or phrases in a search, documents that contain both items have relevance ranking higher than documents that contain just one of them. When you use the Proximity option, the closer the occurrences of matches for your query are within a document, the higher the relevance ranking for the document.