An-Najah Staff

Annotation of Web contents is becoming a fundamental activity by which users appropriate and enrich information available on the Net. MADCOW (Multimedia Annotation of Digital Content Over the Web) is a system for annotating HTML pages that provides a uniform interactive paradigm to make annotations on text, images and video. MADCOW has also recently included novel features for groups and group annotations by adopting ontological domains, but interaction with the MADCOW client is currently limited to the use of common input devices (e.g., keyboard, mouse), requiring a precise selection of the material to be annotated. In this paper, we present a sketch-based interface, which can be used not only to annotate content but also aspects relative to the presentation of the information. While interacting with a standard Web browser, users can draw free-hand geometrical shapes (e.g., circles, closed paths) for selecting specific parts of the Web pages to be annotated. The interaction mode depends on the adopted input device. For example, users interacting with touch-screen devices (e.g., smartphones, tablets) can draw shapes with their fingers, but in principle any device able to detect sketching gestures can be supported (e.g., graphic tablets, optical pens).