In trials before the small claims court, witnesses shall be sworn. The general district court judge shall conduct the trial in an informal manner so as to do substantial justice between the parties. The judge shall have the discretion to admit all evidence which may be of probative value although not in accordance with formal rules of practice, procedure, pleading or evidence, except that privileged communications shall not be admissible. The object of such trials shall be to determine the rights of the litigants on the merits and to dispense expeditious justice between the parties.