Superspace techniques are used to formulate a supersymmetric model on an AdS3 surface embedded in four dimensions. In this model, the supersymmetry transformation is the "square root" of the transformation generated by the isometry generators of AdS3. Since momentum is not an isometry generator, supersymmetry does not result in equal masses for a Bosonic field and its Fermionic partner. We express this model in terms of coordinates that characterize the AdS3 space. In one coordinate system, it is possible to define a subspace with a Minkowski metric. It becomes possible to infer a model in AdS4 space in which there is a symmetry transformation that relates Bosonic and Fermionic fields. This model is not a consequence of being formulated in superspace and the Fermionic transformation is not the "square root" of an isometry of AdS4.