In last decade serious effort has also been made towards mining of evolving data-sets and now several one pass algorithms with restricted memory footprints are available for use in data stream environments. Study of temporal evolution of the patterns has been recognized as an important next generation data mining problem by both - the research and user communities. Comparative analyses of the changes detected in the discovered trends over the temporal dimension are likely to provide an insight into the dynamics of the dgp. Different levels of abstractions from the end-user’s viewpoint, form the second dimension of such analyses.