  Software engineers working in large projects must navigate complex
information landscapes. Change Impact Analysis (CIA) is a task that relies on
engineers' successful information seeking in databases storing, e.g., source
code, requirements, design descriptions, and test case specifications. Several
previous approaches to support information seeking are task-specific, thus
understanding engineers' seeking behavior in specific tasks is fundamental. We
present an industrial case study on how engineers seek information in CIA, with
a particular focus on traceability and development artifacts that are not
source code. We show that engineers have different information seeking
behavior, and that some do not consider traceability particularly useful when
conducting CIA. Furthermore, we observe a tendency for engineers to prefer less
rigid types of support rather than formal approaches, i.e., engineers value
support that allows flexibility in how to practically conduct CIA. Finally, due
to diverse information seeking behavior, we argue that future CIA support
should embrace individual preferences to identify change impact by empowering
several seeking alternatives, including searching, browsing, and tracing.
