In Peel's personal injury action, Wilson, a physician who had no previous knowledge of the matter, sat in court and heard all the evidence about Peel's symptoms and conditions. Wilson is called to give her opinion whether Peel's injuries are permanent. May Wilson so testify?
Yes, provided she first identifies the data on which her opinion is based.  Yes, because an expert may base her opinion on facts made known to her at the trial.  No, because she has no personal knowledge of Peel's condition.  No, because permanence of injury is an issue to be decided by the jury.