  To improve the usability of a revision history, change untangling, which
reconstructs the history to ensure that changes in each commit belong to one
intentional task, is important. Although there are several untangling
approaches based on the clustering of fine-grained editing operations of source
code, they often produce unsuitable result for a developer, and manual
tailoring of the result is necessary. In this paper, we propose
ChangeBeadsThreader (CBT), an interactive environment for splitting and merging
change clusters to support the manual tailoring of untangled changes. CBT
provides two features: 1) a two-dimensional space where fine-grained change
history is visualized to help users find the clusters to be merged and 2) an
augmented diff view that enables users to confirm the consistency of the
changes in a specific cluster for finding those to be split. These features
allow users to easily tailor automatically untangled changes.
