Data that is more free-form, such as multimedia files, images, sound files, or unstructured text. Unstructured data does not necessarily follow any format or hierarchical sequence, nor does it follow any relational rules. Unstructured data refers to masses of (usually) computerized information which do not have a data structure which is easily readable by a machine. Examples of unstructured data may include audio, video and unstructured text such as the body of an email or word processor document. Data mining techniques are used to find patterns in, or otherwise interpret, this information. Merrill Lynch estimates that more than 85 percent of all business information exists as unstructured data – commonly appearing in e-mails, memos, notes from call centers and support operations, news, user groups, chats, reports, letters, surveys, white papers, marketing material, research, presentations, and Web pages (“The Problem with Unstructured Data.”)

Source: US OD