Judge Saffman sitting as a Judge of the High Court had this to say concerning the Assessment of Credibility.
110. In Thornton v NIHE  NIQB 4 Gillen J suggested that the court must pay attention to these factors:
- The inherent probability or improbability of representations of fact;
- The presence of independent evidence tending to corroborate or undermine any given statement of fact;
- The presence of contemporaneous records;
- The demeanour of witnesses
- The frailty of the population at large in accurately recollecting and describing events in the distant past
- Does the witness take refuge in wild speculation or uncorroborated allegations of fabrication?
- Does the witness have a motive for misleading the court?
111. In Mumtaz Properties v Ahmed  EWCA 610 it was recognised that there were many situations in which the court was asked to assess the credibility of witnesses from their oral evidence. That task was not to be carried out merely by reference to the impression that a witness made giving evidence; it was not solely a matter of body language or tone of voice or other factors that might generally be called the “demeanour” of a witness. The judge should consider what other independent evidence was available to support the witness. Such evidence would generally be documentary but could be other oral evidence. Contemporaneous written documentation was of the greatest importance in assessing credibility…
Reference was also made to ‘the Judge as Juror’ see here.