Ontologies

Visualize the ontology diagram

The diagram draws your ontology as a picture: each class is a box, each relationship is a line between two boxes, and each box lists or counts its attributes. It is the quickest way to see the shape of a model and spot what’s missing.

In the app: Data Context › Ontologies › your ontology › Diagram

[screenshot]
The diagram with several connected classes, the control strip along the top, and a class panel open on the right.

Before you start

Anyone who can open the ontology can view the diagram. Editing on the canvas needs write access to the organization; see Edit on the canvas.

What the diagram shows

  • Classes are the boxes.
  • Relationships are the lines, drawn from the class a relationship applies to toward the class it points to.
  • Attributes appear on each box, as counts or as a list (see below).
  • Instances are not drawn. They are counted on each box and listed in the workbench.

The first time you open a diagram, Kenseme arranges the boxes automatically so connected classes sit near each other. If the ontology has no classes yet, you see Nothing to diagram yet with an Add Class button.

Use Back to ontology to return to the workbench.

Choose what each box shows

The Counts / Attributes switch changes every box at once:

  • Counts (the default) shows how many attributes, relationships, and instances each class has. Good for a large model.
  • Attributes lists each attribute on its box. Good when you want to read the fields.

Switching doesn’t move anything on the canvas.

Find your way around

  • Search classes: type in the Search classes… box. Matching boxes are highlighted and the first match is centered.
  • Select a class: click a box to open its panel on the right. The panel shows the class’s identifier, description, attributes, and relationships. Every name in the panel is a link that opens that item in the workbench.
  • Select a relationship: click a line. The panel shows what it Connects and, if set, what it is the Inverse of.
  • Focus: click Focus this class in the class panel. The diagram narrows to that class and its neighbors. Hops (0 to 5) sets how far out the neighborhood reaches; 1 shows direct neighbors. Clear focus returns to the full graph.
  • Hide unconnected: hides classes that have no relationships.
  • Zoom: the zoom buttons, Fit to fit the whole graph in the window, and Reset to re-run the automatic arrangement.

Tip: If the graph looks tangled, turn on Hide unconnected, focus one important class, and set Hops to 1 or 2.

You can also arrive already focused: View in Diagram on a class’s Neighborhood card in the workbench opens the diagram centered on that class.

Your layout is saved

Kenseme remembers where you put the boxes, and your zoom and position, separately for each person. When you come back, the diagram opens the way you left it. Classes added since then are placed next to a related class.

Reset throws away your saved arrangement and lays the diagram out fresh. It affects only your own view; colleagues keep theirs.

Note: Zoom and position are saved from the full graph only. Moving around while a class is focused, or in the large-ontology overview, doesn’t change your saved view.

Large ontologies

An ontology with about 300 classes or more opens in an overview instead of drawing every box. The overview offers:

  • The search box, to jump to one class.
  • A Most connected list of classes; click one to open its neighborhood.
  • Show entire graph, which draws everything. The button warns that this may be slow.

Edit on the canvas

A View / Edit switch appears in the control strip for members with write access. It starts on View, so you can’t change anything by accident. It is disabled while the organization is in read-only mode.

Switch to Edit to work on the canvas:

To do this Do this
Add a class Click Class in the Add group, or right-click empty canvas and choose Add class here.
Add an instance Click Individual in the Add group. Instances aren’t drawn, so a message confirms it was created.
Rename a class Double-click its title and type. This changes the display name (label), not the identifier.
Add an attribute Hover a box and click +, click + next to Attributes in the class panel, or right-click the box and choose Add attribute.
Add a relationship Drag from one class onto another, click + next to Relationships in the class panel, or right-click a box and choose Add relationship. The relationship dialog opens with the classes filled in.
Reconnect a relationship Drag the end of a line onto a different class.
Delete Hover a box or line and click the trash icon, right-click and choose Delete class or Delete relationship, or click Delete class in the class panel.
Delete several items Shift-, Ctrl-, or Cmd-click to select more than one, then press Delete or Backspace. One confirmation covers the whole selection.

Every change is saved to the ontology as you make it, and the diagram redraws from what was saved. New relationships follow the same naming rule as in the workbench: identifiers are stored in lowerCamelCase. See Edit an ontology.

Undo on the canvas

  • After you add something, an Undo button appears in the control strip for a few seconds. It removes exactly what you added.
  • After a delete, a Restore from version history button appears for a few seconds instead. It opens the ontology’s versions.

Warning: The Remove attribute and Remove relationship icons in the class panel delete that attribute or relationship from the whole ontology, not only from this class. They ask for confirmation first.

Warning: A delete removes the item and every statement that refers to it. The canvas has no one-click undo for deletes. You can undo it from More › Recent changes on the ontology page, unless the deleted item had bindings; that undo is refused. Otherwise, fall back to a version. Create a version before a large cleanup.

If you’d rather describe changes in words, the ontology assistant can make the same edits from a chat.