Now with less set theory! Annotations Now with less set theory!

Outline What are annotations Paper v Digital Limits of Paper annotations Forms of Digital annotations Features of Digital annotations Sources of Digital annotations Problems of Digital annotations Solutions

What are annotations Additional content that is related to a document Traditionally created by a person writing notes in the margins of documents As document creation is becoming digital so is annotation of documents Mindlessly copying the traditional format into the digital world is a significant underutilisation of the digital potential

What are annotations Are created for an almost limitless number of reasons Whether their creator intended them solely for their benefit, or to benefit other people is not as fundamental as it may seem Paper annotations are presumably intended only for the use of their creator However they can still end up being useful to others, even to the point of being annotated themselves

Paper v Digital Paper annotations Only written/drawn annotations possible Restricted by availability of blank space Tied to exact document they are created on Digital Annotations Almost any form imaginable possible Not restricted by properties of source document Not tied to document used to create them

Limits of Paper annotations People with a different copy of the annotated document can’t make use of them Once annotations are made they can’t be changed without wasting available space If an annotated document is reused irrelevant annotations can’t be removed

Forms of Digital Annotations Annotation types Text Audio Video Pictures Links Uses Content Metadata

Features of Digital Annotations Can refer to the entire document or only a specific part Can refer to more than one document in a collection Can have access restrictions Can be stored separately to annotated documents Can persist when the annotated document is changed

Features of Digital Annotations Can be edited after creation Can’t make it impossible for other annotations to be added to a document Can’t (without access restrictions) prevent annotations from being shared among multiple readers of the same document Can’t be forced on users of rare documents Can be added to newly created paper copies of documents

Sources of Digital Annotations Individual people Manual annotations Usually informal, unstructured Automated systems Automatic annotations Usually formal, structured Crowd-sourcing Created by input of groups of people, not just individuals Potentially automatically extracted from human input

Problems for Digital Annotations Linking annotations to documents Type and direction of links affects usability of annotations Annotated documents can be changed without warning Method for anchoring annotations within documents must be able to deal with change Access restrictions can be confusing Limiting what types of annotations can be made, especially on existing annotations

Problems for Digital Annotations Editing annotation links can create cycles Not possible to identify order in which annotations were created Lack of consequences for creating “bad” annotations Spam Trolling Flame wars

Solutions Link types affect usability of annotations Uni-directional links are bad Bi-directional links are good Documents can be changed without warning Record versions of documents that annotations were created against Include algorithms for updating annotation anchors in response to changed documents

Solutions Access restrictions can cause confusion Attempting to create a public annotation on a specific part of a (semi)-private annotation doesn’t make sense Good error messages/notification of access level Editing annotations can cause cycles Include cycle checker as part of process for saving edits to annotations Don’t allow annotation links to be created during editing

Solutions No consequences for “bad” annotations Not easily solvable by automated system Solutions not really within scope of project