## 2 Case Studies  
### Annotations for Electronic Scholarly Editions  
Scholarly editions are the outcome of detailed study of a specific literary work or collection of shorter works such as poems or short stories. When preparing a scholarly edition, scholarly editors aim to provide a comprehensive description of the history of the literary work(s) including information about significant versions and physical forms. The IFLA FRBR model, which allows bibliographic entities to be described as Works, Expressions, Manifestations or Items [12] can be used as a foundation for describing these versions. Versions can be represented as FRBR Expressions, while each issue of a given version can be represented as a FRBR Manifestation. Physical characteristics of specific physical objects such as manuscripts are described at the FRBR Item level. In addition, a scholarly edition usually comprises a textual essay, textual notes that analyse variations and editorial decisions, and a textual apparatus that is compiled to record the alterations made between different versions of the work. Annotations can be used to document these textual notes and variations, and can provide an additional layer of information about the documents being studied, and the people or organizations who were involved in the production of the work over time. Annotations in the form of explanatory notes may also address the content of the text, identifying such things as allusions to other works, historical contexts and stylistic significance. Modern scholarly editions are increasingly collaborative exercises that involve a team of editors, advisors and editorial board members dispersed globally. The AustESE project [13] is a collaboration between The University of Queensland, University of NSW, Curtin University, University of Sydney, Queensland University of Technology, Loyola University, Chicago and the University of Saskatchewan, which aims to develop a set of interoperable services to support the production of electronic scholarly editions by distributed collaborators in a Web 2.0 environment. The annotation service that we are developing for the AustESE project enables scholarly editors to:  
* Create annotations that relate transcripts with facsimiles;
* Attach notes to text and image selections;
* Reference secondary sources;
* Annotate textual variations--record information about the reason for or the source of the variation;
* Engage in collaborative discussion about texts through comments, questions and replies. To support these use cases, we have defined several custom subclasses of the OA _Annotation_ class including: _ExplanatoryNote_ to provide explanatory commentary on selected characters, words, paragraphs, sections etc. ; _TextualNote_, to document or provide support for editorial decisions; and _VariationAnnotation_ to describe textual variations between multiple versions of a literary work. When a scholarly editor creates a _VariationAnnotation_, the content of the Annotation includes an assertion that there is a directional relationship between two versions (the original and the edited); and commentary and/or metadata (e.g., the responsible agent, the date of the variation, the reason for the variation), which applies to the asserted relationship: it does not apply to the versions individually. Figure 2 shows an example of a _VariationAnnotation_. The Body (ex:rem1) is an OAI ORE Resource Map [14] that reifies the _isVariantOf_ relationship that the scholar is attaching between the original and variant texts. Our use of ORE Resource Map to reify a relationship between resources was inspired by the way that the OA Annotation class reifies the _oa:annotates_ relationship between body and target resources. The properties and relationships displayed in blue (at the bottom of Figure 2) are encapsulated within the Body, whilst those at the top of Figure 2, exist within the _Annotation_ graph. As an ORE Resource Map, the Body resource can be identified by a URI and can be reused outside of the context of the Annotation.