Resolving information on algol systems

Our awareness of the facts on Algol systems, arising from both statistical evidence and examination of particular examples, is presented. The statistical information derives from the author's recent catalogue of Algol-type candidate stars. The particular cases of R Ara and W Cru are considered. The presence of undiscerned background factors in these systems exemplify persistent threats to the confidence we place on parameter sets characterising any models we may form of such objects.