Visualization as a Key Factor for the Usability of Linguistic Annotation Tools
Abstract Linguistic annotation is an important means of adding information to corpora of spoken or written language. While some less complex annotation tasks can be performed automatically, a great number of annotation tasks require manual annotation, which is typically very time-consuming and tedious. As a consequence, tools for manual annotation tasks should provide a user-friendly interface that makes the annotation process as convenient and efficient as possible; in other words, usability should play an important role in the design of such tools. This article contributes to the field of “visual linguistics” by investigating the role of visualization in linguistic annotation tools with regard to good and bad usability practices. While there are several studies that are dedicated to visualizing linguistic results, visualization in the context of linguistic annotation has so far been largely neglected. Accordingly, a heuristic walkthrough evaluation study with 11 annotation tools was conducted to find out about typical usability problems. It showed that many of the usability issues identified during the evaluation are related to aspects of interaction design. However, there are also a large number of usability issues that are directly connected to aspects of visualization and visual design. These aspects of good and bad visualization are discussed by means of existing usability heuristics, which can be used to illustrate and explain how and why visualization inf luences the usability of linguistic annotation tools.