Spotting the difference

摘要

Source Code Management (SCM) is a valuable tool in software development projects, providing the ability to store and retrieve past versions of source files. Comparison tools offer the capability to compare different files or versions, highlighting their differences. Most such tools are built around a two-pane interface, with files displayed side by side. Such interfaces are inefficient in the use of horizontal screen space, and ineffective since duplication makes text more difficult to read, leaving most of the comparison burden to the user. In this article we introduce an innovative metaphor for comparison interfaces. Based on a single-pane interface, common text is displayed only once with differences intelligently combined into a single text, improving readability. To further improve usability, additional features were developed: difference classification {additions, deletions, and modifications); fine level of granularity; special features to display modifications; and intelligent white space handling. A usability study conducted among 16 participants using real-world samples demonstrated the interface adequacy: on average, participants were 60% faster in performing comparison tasks, while the quality of answers improved by almost 80% on our scale. After the experiment, the proposed interface was declared the favorite choice by all participants. file comparison; usability; graphical user interface (GUI); Java; Eclipse