There have been recent improvements in document technologies like the standardization of object interfaces to access and manipulate the properties of web documents. There has also been significant progress in pen based computing for recognition of digital ink in desktops, tablets and handheld devices. These have necessitated a need for further research on annotation architectures for digital documents, specifically penbased annotation systems. This paper presents an attempt to leverage the new standards of DHTML and W3C DOM that are being gradually implemented by popular browsers, to build a prototype of an ink annotation system with common components across browsers. One of the primary goals in this study is to semantically link ink data with underlying document elements like text and images. The system has three components: a) Ink capture and rendering b) Ink Understanding, which recognizes and associates ink with the underlying document and c) Ink storage and retrieval. 1.

Most co-authoring tools support basic annotations, such as edits and comments that are anchored at specific locations in the document. However, they do not support metacommentary about a document (such as an author’s summary of modifications) which gets separated from the document, often in the body of email messages. This causes unnecessary overhead in the write-review-edit workflow inherent in co-authoring. We present document-embedded structured annotations called “bundles ” that incorporate the meta-commentary into a unified annotation model that meets a set of annotation requirements we identified through a small field investigation. A usability study with 20 subjects evaluated the annotation reviewing stage of coauthoring and showed that annotation bundles in our highfidelity prototype reduced reviewing time and increased accuracy, compared to a system that only supports edits and comments. Author Keywords Collaborative writing, collaborative authoring, structured

We present a study of the degree to which annotations overlap when several researchers read the same set of scientific articles. Our objective is to determine whether there is sufficient evidence to suggest that information about which passages initial readers tend to annotate might be used to recommend important passages to later readers of the same material. We found that readers exhibit a high degree of overlap in the passages they annotate, that these passages account for a small but significant fraction of the total document, and that such passages are distributed throughout a document rather than concentrated in the same few sections in each paper (e.g., the results section). These findings indicate that work on developing a passage recommendation model based on annotation is warranted.

Most co-authoring tools support basic annotations, such as edits and comments anchored at specific locations in the document. However, they do not sup-port higher-level communication about a document such as commenting on the tone of a document, giving more explanation about a group of basic annota-tions, or having a document-related discussion. Such higher-level communica-tion gets separated from the document, often in the body of email messages. This causes unnecessary overhead in the write-review-edit workflow inherent in co-authoring. To address the problem, we first established user-centered requirements for annotation support. We conducted a small field investigation of email exchanges including document attachments, among three small groups of academics (3 to 5 people each). We categorized the higher-level communication from the email and developed a set of eleven requirements to support document annotations. We next developed document-embedded structured annotations called “bundles” that incorporate higher-level communication into a unified annotation model meeting the set of requirements. We also designed and implemented a high-fidelity prototype called the “Bundle Editor ” that illustrates our structured annotation model. Finally, we conducted a usability study with 20 participants to evaluate the annotation reviewing stage of co-authoring. The study showed that the annota-tion bundles in our high-fidelity prototype reduced reviewing time and increased accuracy, compared to a system that supports only edits and comments. ii