Content items may be segmented and labeled by topic to provide for the capture, analysis, indexing, retrieval and/or distribution of information within information rich media, such as audio or video, with greater functionality, accuracy and speed. The segments and other related information may be stored in a database and made accessible to users through, for example, a search service and/or an on-demand service. Automatic segmentation may include receiving a text representation, calculating relevance intervals based on the text representation, determining a nodal representation based on the relevance intervals, and determining segments of the content item based on the nodal representation.