1 As multimedia system integrate a variety of temporally interrelated media items, synchronization is an important issue in those systems. One part of synchronization is the representation of temporal information. Time models are needed to specify temporal interrelations. With the emerging interactive media, deterministic models are replaced by indeterministic models with more expressiveness. Therefore, this paper classifies and evaluates a selection of the most common existing models by their expressiveness. Additionally, a temporal model based an temporal operaproposed providing high-level abstractions and a high degree of expressiveness for multimedia systems.