computer science

Web annotation

Web annotation is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Web annotation rather than just read about it. In short: Web annotation can refer to online annotations of web resources such as web pages or parts of them, or a set of W3C standards developed for this purpose. The term can also refer to the creations of annotations on the World Wide Web and it has been used in this sense for the annotation tool INCEpTION, formerly WebAnno.

Key takeaways

Web annotation belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Web annotation to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Web annotation from memory before moving on to harder problems.

Reference excerpt

Web annotation can refer to online annotations of web resources such as web pages or parts of them, or a set of W3C standards developed for this purpose. The term can also refer to the creations of annotations on the World Wide Web and it has been used in this sense for the annotation tool INCEpTION, formerly WebAnno. This is a general feature of several tools for annotation in natural language processing or in the philologies.

Annotation of web resources With a web annotation system, a user can add, modify or remove information from a Web resource without modifying the resource itself. The annotations can be thought of as a layer on top of the existing resource, and this annotation layer is usually visible to other users who share the same annotation system. In such cases, the web annotation tool is a type of social software tool. For Web-based text annotation systems, see Text annotation. Web annotation can be used for the following purposes:

to rate a Web resource, such as by its usefulness, user-friendliness, suitability for viewing by minors. to improve or adapt its contents by adding/removing material (like wiki). as a collaborative tool, e.g. to discuss the contents of a certain resource. as a medium of artistic or social criticism, by allowing Web users to reinterpret, enrich or protest against institution or ideas that appear on the Web. to quantify transient relationships between information fragments. to save, retain and synthesize selected information. Annotations can be considered an additional layer with respect to comments. Comments are published by the same publisher who hosts the original document. Annotations are added on top of that, but may eventually become comments which, in turn, may be integrated in a further version of the document itself.

Web Annotation standard In the Web Annotation standard,

[a]n annotation is considered to be a set of connected resources, typically including a body and target, and conveys that the body is related to the target. The exact nature of this relationship changes according to the intention of the annotation, but the body is most frequently somehow "about" the target. (...) The (...) model supports additional functionality, enabling content to be embedded within the annotation, selecting arbitrary segments of resources, choosing the appropriate representation of a resource and providing styling hints to help clients render the annotation appropriately.

The basic data structures of Web Annotation are

target (the element being annotated, e.g., a web document or a part of it), body (the content of the annotation, e.g., a string value), and annotation (the element that serves to relate body and target of an annotation) The body can be a literal value or structured content (a URI). The target can be identified by an URI (e.g., fragment identifiers) and/or a selector that defines a domain-, resource- or application-specific access protocol, e.g., offset-based, XPath-based, etc. Web Annotation was standardized on February 23, 2017 with the release of three official Recommendations by the W3C Web Annotation Working Group:

Web Annotation Data Model Web Annotation Vocabulary Web Annotation Protocol These recommendations were accompanied by additional working group notes that describe their application:

Embedding Web Annotations in HTML Selectors and States The Web Annotation data model is also provided in machine-readable form as the Web Annotation ontology. Note that this ontology defines the Web Annotation namespace (https://www.w3.org/ns/oa#), and that this namespace is conventionally abbreviated as oa. This is the abbreviation for Open Annotation, a W3C Community Group whose specifications formed the basis for the Web Annotation standard. Web Annotation supersedes other standardization initiatives for annotations on the web within the W3C, e.g., the earlier Annotea project discontinued after 2003.

Related specifications Web Annotation can be used in conjunction with (or as an alternative to) fragment identifiers that describe how to address elements within a web document by means of URIs. These include

RFC 5147 (URI fragment identifiers for the text/plain media type) RFC 7111 (URI fragment identifiers for the text/csv media type) RFC 8118 (URI fragment identifiers for the application/pdf media type) SVG fragment identifiers XPointer (for addressing components of XML documents) Media Fragments (for addressing components of media files) Other, non-standardized fragment identifiers are in use, as well, e.g., within the NLP Interchange Format. Independently from Web Annotation, more specialized data models for representing annotations on the web have been developed, e.g., the NLP Interchange Format (NIF) for applications in language technology. In early 2020, the W3C Community Group "Linked Data for Language Technology" launched an initiative to harmonize these vocabularies and to develop a consolidated RDF vocabulary for linguistic annotations on the web.

Web Annotation Systems

Comparison of web annotation systems Many of these systems require software to be installed to enable some or all of the features below. This fact is only noted in footnotes if the software that is required is additional software provided by a third party.

Discontinued web annotation systems

See also Comparison of notetaking software Social bookmarking Some reference management software packages also support web annotations Backlinks Online deliberation Perusall Folksonomy Metadata Threaded discussion Virtual graffiti Comparison of software saving Web pages for offline use

References

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Web annotation

Start with the simplest possible case. Write down what Web annotation claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Web annotation before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Web annotation ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Web annotation

In research: Web annotation appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Web annotation in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Web annotation is common in secondary-school and first-year university syllabi. It links to neighbouring topics Social software, Web annotation, Web software, so understanding it makes those chapters shorter.
In everyday life: Look for Web annotation outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Web annotation in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Web annotation means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Web annotation out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Web annotation in simple terms?

Why does Web annotation matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Web annotation?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Web annotation.