An opening statement is generally the first occasion that the trier of fact (jury or judge) has to hear from a lawyer in a trial, aside possibly from questioning during voir dire. The opening statement is generally constructed to serve as a "road map" for the fact-finder. This is especially essential, in many jury trials, since jurors (at least theoretically) know nothing at all about the case before the trial, (or if they do, they are strictly instructed by the judge to put preconceived notions aside). Though such statements may be dramatic and vivid, they must be limited to the evidence reasonably expected to be presented during the trial. Attorneys generally conclude opening statements with a reminder that at the conclusion of evidence, the attorney will return to ask the fact-finder to find in his or her client's favor.