This may involve figuring out new or tweaked markup for talking about subsections of content.

Here's a rough draft with an example (a simplistic fact-check of a claim made by Obama within a much longer speech): https://gist.github.com/danbri/96d6265756577e5f21ad4141f053b76d

DesignIssues:

• how to say when a clip starts? e.g. startTime? (definition needs adjusting)
• endTime? or custom URLs?
• how to represent duration? are we explicit that this is seconds? or e.g. milliseconds?
• we can also point to transcripts, but don't need to.

We'll need conventions for e.g. whether the item-reviewed is the smallest part (the Clip) or the larger (e.g. a TV Episode or VideoObject).

(Aside: Google's structured data testing tool complains a lot - this can be addressed elsewhere)