Metaheuristic approaches to examination timetabling problems are usually split up into two phases: initialisation phase in which a heuristic is employed to construct an initial solution and improvement phase which employs a metaheuristic. Different hybridisations of metaheuristics with sequential heuristics are known to lead to solutions of different quality. A Case Based Reasoning CBR methodology has been developed for selecting an appropriate hybridsation of Great Deluge metaheuristic with a sequential construction heuristic. In this paper we propose a new similarity measure between two timetabling problems that is based on fuzzy sets. The experiments were performed on a number of real-world problems and the results were also compared with other state-of-theart methods. The results obtained show the effectiveness of the developed CBR system.