▶ EM Language: Canvas, Metadata and Epochs (~~4 min)
| **Clip:** 07 | **Duration:** ~4 min | **Recording segment:** ~33:30 → ~38:00 ---- Prerequisites ------------- :doc:`06-archaeological-workflow` Overview -------- The EM canvas is the root container for all data. It carries metadata fields (human ID, author, ORCID, licence, embargo) that propagate to all leaf nodes. Epochs are swim-lane containers representing chronological or interpretive phases — they do not require absolute dates. .. figure:: /_static/screenshots/clip_07/0001_fictional_em_canvas.jpg :alt: A fictional EM canvas showing all metadata fields. :width: 90% A fictional EM canvas showing all metadata fields. Key Concepts ------------ - The canvas is the root node of every Extended Matrix. - Metadata set on the canvas propagates automatically to all child nodes. - Epochs are interpretive containers — they can be relative phases, not just calendar dates. - Periodization is an act of interpretation and must be traceable via paradata. Screenshots ----------- .. figure:: /_static/screenshots/clip_07/0003_orcid_licence_embargo.jpg :alt: Metadata fields: ORCID, licence type, and embargo date. :width: 90% Metadata fields: ORCID, licence type, and embargo date. .. figure:: /_static/screenshots/clip_07/0004_swim_lanes_epochs_yed.jpg :alt: Epochs displayed as swim lanes in the yEd graph editor. :width: 90% Epochs displayed as swim lanes in the yEd graph editor. .. figure:: /_static/screenshots/clip_07/0005_metadata_propagation.jpg :alt: Metadata propagation from canvas to all leaf nodes. :width: 90% Metadata propagation from canvas to all leaf nodes. Try It Yourself --------------- In yEd, create a new canvas with your site code as the human ID and add two epochs: one for construction, one for destruction. .. note:: A video walkthrough for this tutorial will be available on the Extended Matrix YouTube channel. .. seealso:: :doc:`Creating Your First Extended Matrix