  A data graph is a convenient paradigm for supporting keyword search that
takes into account available semantic structure and not just textual relevance.
However, the problem of constructing data graphs that facilitate both
efficiency and effectiveness of the underlying system has hardly been
addressed. A conceptual model for this task is proposed. Principles for
constructing good data graphs are explained. Transformations for generating
data graphs from RDB and XML are developed. The results obtained from these
transformations are analyzed. It is shown that XML is a better starting point
for getting a good data graph.
