A generic interface environment for users seeking to interact with and manipulate complex data sets is described. The design is based on the paradigm of a layered 3D visual environment which depicts a current context within the data set, using the notions of `above', `below', `beside', and `beyond'. This environment facilitates user exploration of the data, by selecting operations available in the current context, or by invoking `specialization' or `generalization' transitions to another context in the adjacent layers. The environment has been implemented with user and administrator modes of operation. Two examples of use of the environment are given for typical applications.