Figure 1 shows a hierarchy of three submodels. Motives behind establishing hierarchies in the DEDS modeling of different exploration tasks includes reducing the search space of the observer and exhibiting modularity in the controller design. This is done through the designer, who subdivides the task space of the exploring robot into separate submodels that are inherently independent. Key events cause the transfer of the observer control to new submodels within the hierarchical description. Transfer of control through the observer hierarchy of models allows coarse to fine shift of attention in recovering events and asserting state transitions.