The search above results in 112 patents. The search above results in 129 patents. Group of words enclosed in quotation marks are treated as a single search term. The search above results in 258 patents. She then surmises that requiring the words mouse and trap to be adjacent may be too restrictive.
Parentheses clarify the search expression.
In the absence of parentheses, all operators associate from left to right. The search above results in 3530 patents, most of which do not pertain to rodent traps. At this point, she may wish to try a more restrictive search expression, such as an expression that only finds documents having the word mouse in the Title of the Invention. Conversely, she may also surmise that some relevant documents may not have the word mouse at all, and may instead use the plural or a synonym. Thus, seaching may require substantial thought and experimentation.