Apple and Samsung bosses failed to reach a settlement in last-minute talks yesterday, so the patent trial between the two mobile giants will proceed to a jury verdict. And both companies stand to lose millions - even billions - if the case goes against them.

Presiding judge Lucy Koh has encouraged Apple and Samsung to settle out of court, warning them of the substantial risks they would run by allowing the case to proceed to a jury verdict.

The involvement of the jury, indeed, has been one of the most controversial elements of this complex case: few industry observers believe that members of the California public without training or experience in the mobile technology or patent law fields will be able to grasp the nuances of Apple and Samsung's arguments.

Nevertheless, Judge Koh instructed the jurors to use "the eyes of an ordinary observer" when evaluating whether patents had been violated.

Apple Samsung patent trial

The jurors will have to fill in lengthy forms to indicate their judgement of the many aspects of the case. It's no mean feat: the form is 22 pages long with 36 'question' sections made up of more than 700 individual questions. As my colleague Martyn Williams writes elsewhere:

"Question one alone - "For each of the following products, has Apple proven by a preponderance of the evidence that Samsung Electronics Co. (SEC), Samsung Electronics America (SEA), and/or Samsung Telecommunications America (STA) has infringed Claim 19 of the '381 Patent?" - has 57 individual boxes that need to be filled in."

Other sections of the form ask jurors to indicate what they believe would be a fair figure for damages. Apple has sought $2.5bn in damages, while Samsung requested just $422m.

Closing arguments are scheduled for today, and the jury will then begin its deliberations.

See also:

Everything you need to know about Apple vs Samsung

Apple v Samsung: day by day account of patent trial: UPDATED