“Applying the rational model of law, we would like to think that jurors would evaluate the credentials, the methodology, and the strength of the conclusions offered, and compare the competing experts based upon the appropriate standards of the field.  That would be rational, but alas, not really typical in the courtroom,” says Dr. Ken Broda-Bahm in his article “When Crossing or Responding to Your Opposing Expert Witness,” Look for the L.I.E.”  L.I.E. stands for “Large Internal Error” and that is what attorneys look for to cut down opposing experts credibility.  According to Broda-Bahm, L.I.Es are:

• Large.  A minor or inconsequential mistake could easily be seen as a distraction. 
• Internal to that expert's own methods and approach. 
• An Error - a mistake, miscalculation, exaggeration, omission, or a bungle.