Unstructured data can be textual or non-textual. Textual unstructured data is generated in media like verbal transcriptions, email messages, PowerPoint presentations, Word documents, collaboration software and instant messages. Non-textual unstructured data is generated in media like JPEG images, MP3 audio files and Flash video files.
Signals currently is focused on analyzing the former, a.k.a. textual data, with their corresponding Structured Values (e.g., numerical values or categorical attributes).