Expert witnesses are granted a privileged status in court trials: They are permitted to render opinions or conclusions based on facts admitted into evidence and other information on which they choose to reasonably rely. The expert's privilege is a major exception to the "personal knowledge rule." which normally limits witness testimony to matters of personal knowledge. Being able to testify on anything on which they can reasonably rely permits experts to base their conclusions on their own experience, their technical knowledge, and sometimes even hearsay evidence that would not directly be admitted into evidence. This makes experts a powerful force in the courtroom. REQUIRED: Evaluate the factors that must be considered in the selection an expert witness