An action which might occur in scientific data or narrative. The definition is deliberately vague, intending to collect examples of possible usage. Thus an action could be addition of materials, measurement, application of heat or radiation. The content model is unrestricted. action iself is normally a child of actionList

The start, end and duration attributes should be interpreted as

• XSD dateTimes and XSD durations. This allows precise recording of time of day, etc, or duration after start of actionList. A convention="xsd" attribute should be used to enforce XSD.
• a numerical value, with a units attribute linked to a dictionary.
• a human-readable string (unlikely to be machine processable)

startCondition and endCondition values are not constrained, which allows XSL-like test attribute values. The semantics of the conditions are yet to be defined and at present are simply human readable.

The order of the action elements in the document may, but will not always, define the order that they actually occur in.

A delay can be shown by an action with no content. Repeated actions or actionLists are indicated through the count attribute.