Today more and more information is becoming available in unstructured or poorly structured form. Examples of information of this type are textual documents, web pages, videos, images, sounds, blogs, etc. The goal of this course is to enable the student to understand the foundations of dealing with unstructured or poorly structured information. In particular, the aim is to assist the student to get an understanding of some of the techniques for the indexing, retrieval, filtering, clustering, and presentation of textual and multimedia information held in digital archives and/or on the web. From this perspective the course complements what the student learned from a previous course on Database technology, where only structured information is managed.