Usability has been identified as one of the top unsolved challenges to improve a visual presentation of any type of information. The design and implementation of a visualization tool should incorporate usability by design, and the development methodology should incorporate mechanisms to ensure that users are able to recognize the intended patterns. This paper presents the development methodology for an information visualization tool and its evolution as a reaction of the early feedback captured at the iterative evaluation process. The implemented tool, A4Learning, takes the students' tracking information to match similarity among them, and makes use of this information to estimate the students' performance, and to encourage self-reflection.