Annotation

Definition

An annotation is any form of additional information “superposed” on any existing data or document.

Example: If a scientist records her experimental data in a relational database and then marks some “cells” of a table with the comment “consistent with previous findings,” this additionally “marked” information is an annotation.

Key Points

Often annotations are not originally intended to be part of the collected data, and hence no data or schema structure was designed to hold it. Annotating data is a very common practice in science, where scientists would literally “mark” experimental observation with comments and often use annotations to share their opinions in a collaborative study. One can annotate data at the level of whole data sets, groups of data elements (like columns), or values. As larger-scale experiments are conducted and larger collaborations are formed, management of the annotated data becomes a serious challenge. In recent times, the emerging importance of...