Be prepared to offer an appropriate incentive. Write the User's Tasks While there are many steps and features involved in searching, there are a few basic things people should be able to do, and that you should try to include in your user tasks. You will probably find that most users simply type a single keyword or at most two or three words. Complex queries are rare on most sites. Provide a clearly-labeled button near the query entry field.
People expect the Enter key to work too.
Also, opening and reading the pages or documents should be straightforward. Refine or narrow the results. In the tasks you would give the users, you would not actually use the above words. During usability sessions, we often give users a protocol or set of tasks to follow. Writing the tasks is more of an art than a science.