The object-oriented paradigm has a number of widely recognised strengt
hs when applied to data management, but the increased complexity of ac
tual systems compared with their relational predecessors often means t
hat such databases are less readily accessible to non-programmers than
relational systems. A number of proposals have been made for textual,
form-based and graph-based query interfaces to object-oriented databa
ses, but it is clear that a single approach cannot be considered to be
the best, given the wide range of potential user groups, application
domains and tasks. The paper presents a query interface to an object-o
riented database which supports alternative user-level query paradigms
in a fully integrated environment, thereby enabling different categor
ies of user to select a preferred interface paradigm from a list of op
tions. Furthermore, the interface enables users to examine queries wri
tten in one query interface using any of the other interface paradigms
, which is useful for sharing queries in the multi-paradigm context, a
nd for helping users familiar with one approach to learn another. The
system has been prototyped using the ADAM object-oriented database sys
tem, and an experimental comparison of different interaction modes has
been conducted.