Inferences from evidence are drawn according to ordinary common sense. There is a general common-law principle that questions of fact are tried by the jury and questions of law by the judge. Judicial control over the fact-finding process in jury trials is exercised to a large extent through the filtering of the evidence to be presented before the jury and by withholding cases from jury adjudication. The most important concept involved in this exercise is relevance and admissibility. Witnesses are allowed to testify to facts but not to their opinions. The jury must draw its own inferences from the facts stated by the witness; the witness has to confine himself to recounting what happened. When drawing inferences from evidence, the trier of fact inevitably uses generalizations concerning the normal course of events. At the basis of trial procedure lies the idea that the court's function is confined to adjudication on the disputed issues while the litigants are left free to conduct their case. As a general rule, conviction may rest upon the uncorroborated testimony of one witness. When an accused person testifies in his own defense, attention will naturally be focused on his veracity. The law of criminal evidence is concerned with certain aspects of constitutional law such as the privilege against self-incrimination and improperly obtained evidence. Bibliography, table of cases, table of statutes and statutory instruments.