Sketch Recognition User Interfaces: Guidelines for Design and Development
-Alvardo

COMMENT

SUMMARY

In this paper the author presents a sketch recognition based tool for creating PowerPoint diagrams. The author has also performed evaluation of the prototype using several techniques and established design guidelines for creating SkRUIs. The author also evaluates the utility of several techniques used in iterative design of traditional user interfaces, for development of SkRUIs.

The prototype of their application supports drawing naturally on a separate window. These diagrams are then recognised by the SketchREAD recognizer and the recognized diagrams are then imported to the PowerPoint slides. The recognition is done only when the user completes sketching or when the focus is shifted from the sketching window. The system is not capable of determining automatically whether the user has finished sketching and relies on explicit feedback from the user. The system also supports a number of editing features like move and delete. It was found that providing an explicit modal switch between edit and ink gestures confused the users who often forgot to switch modes. Therefore an online edit mode was developed. The user hovered the pen over the drawn ink diagram and a subsequent cursor change indicated that the system was in edit mode. During formative evaluation users expressed the desire to add annotation symbols without them being recognised. A combo box was provided to indicate whether the recognition was ON.

The system was evaluated by testing it on users who were all graduate students. The users were asked to perform three prototypical diagram creation tasks. After completion of these tasks feedback was taken, based on which several design guidelines were established.

(1) Recognition results should be displayed only after sketching is done; (2) Provide explicit indication between free sketching and recognition. (3) Muti-domains should only be used when system is robust enough; (4)Pen based editing should be used. Sketching and editing should have clearly distinguishable gestures. (5)Large buttons should be used for pen based interface (6)Pen should respond in real time.

DISCUSSION

The paper largely deals with UI issues in Sketch based interfaces. The paper established several important hueristics for SkRUIs. It also points out many shorcomings of using traditional iterative design techniques. As achnowledged by the author modal switches are prone to confuse user. Recognized and un-recognized modes confused the users in the study. An automatic method should be developed to identify modes on the basis of implicit cues, as was done in the case of differentiating between editing and drawing gestures.