Information Retrieval

• deals with the representation, storage, organization of and access to information items
• is finding material of an unstructured nature that satisfies an information need from within large collections

• data are strongly structured × documents are not
• documents are meant for human interaction, data are meant for the computer

• physical (form) – to read a digital document, you need suitable tools
• meaning (content) – context is part of the meaning construction
• social (medium) – there's an intention behind every document

• media
  • text (types: book, article, letter)
  • image (types: x-ray, photograph, graphic)
  • video
  • structured documents
• documents can consist of different documents

user's information need expressed using a predefined language

• system should be simple to use
• must give the best possible answers, they must be relevant
• must return reasonable quantities of answers
• must be fast

• user's expertise
• temporal and geographical need

• at document side: document, surrogate, information
• at user side: information need, request, query