Former defense secretary Donald Rumsfeld said there are known knowns -- things people know -- known unknowns -- things people know they don't know -- and unknown unknowns -- things people don't realize they don't know. That pretty much sums up autonomous driving technology these days.

It isn't clear how long it will take the auto industry to deliver truly self-driving cars. Thursday evening, however, investors will get an education about what's state of the art when $Tesla, Inc.(TSLA.US)$ hosts its artificial intelligence day.

The event will likely be live-streamed on the company's website beginning around 5 p.m. Eastern Standard Time. A link to the webcast isn't available yet. The company didn't respond to a request for comment about the agenda for the event.

Much of what will get talked about won't be a surprise, even if investors don't understand it all. Those are known unknowns.

Tesla should update investors about its driver assistance feature dubbed full self driving. What's more, the company will describe the benefit of vertical integration. Tesla makes the hardware -- its own computers with its own microchips -- and its software. Tesla might even give a more definitive timeline for when Level 4 autonomous vehicles will be ready.

Roth Capital analyst Craig Irwin doesn't believe Level 4 technology is on the horizon though. He tells Barron's the computing power and camera resolution just isn't there yet. "Tesla will work hard to suggest tech leadership in AI for automotive," says Irwin. "Reality will probably be much less exciting than their claims."

Irwin rates Tesla shares Hold. His price target is just $150 a share.

Level 3 systems would allow drivers to stop paying attention part of the time. Level 4 would let them stop paying attention most of the time. And Level 5 means the car does everything always. "Level 5 autonomy isn't an easy endeavor," says Global X analyst Pedro Palandrani. There are so many unique cases for technology to tackle, like in bad weather or dirt roads. "But level 4 is enough to change the world." he added. He is more optimistic than Irwin about the timing for Level 4 systems and hopes Tesla provides more timing detail at its event.

Beyond a technology run down and level 4 timing, the company might have some surprises up its sleeve for investors. Palandrani has two ideas.

For starters, Tesla might indicate it's willing to sell its hardware and software to other car companies. That would give Tesla other unexpected, sources of income. Tesla already offers its full self driving as a monthly subscription to owners of its cars. That's new for the car industry and opens up a source of recurring revenue for anyone with the requisite technology. Selling hardware and software to other car companies, however, would be new, and surprising, for investors.

Tesla might also talk about its advancements in robotics. CEO Elon Musk has talked often in the past about the difficulty of making the machine that makes the machine. Some of Tesla's AI efforts might also be targeted at building, and not just driving, vehicles. "We're just making a crazy amount of machinery internally," said Musk on the company's second-quarter conference call. "This is....not well understood."

Those are two items that can surprise. Whether they, or other tidbits, will move the stock is something else entirely.

Tesla stock dropped about 7% over Monday and Tuesday partly because NHTSA disclosed it was looking into accidents involving Tesla's driver assistance features. Tesla will surely stress the safety benefits of driver assistance features on Thursday, whether it can shake off that bit of bad news though is harder to tell.

"Thursday becomes a much more important event in light of this week's [NHTSA] probe," says Wedbush analyst Dan Ives. "This week has been another tough week for Tesla [stock] and the Street needs some good news heading into this AI event."

Ives rates Tesla shares Buy and has a $1,000 price target for the stock. Tesla's autonomous driving leadership is part of his bullish take on shares.

If history is any guide investors should expect volatility. Tesla stock dropped 10% the day following its battery technology event in September 2020. It took shares about seven trading days to recover, and Tesla stock gained about 86% from the battery event to year-end.

Tesla stock is down about 6% year to date, trailing behind the 18% and 15% comparable, respective gains of the S&P 500 and Dow Jones Industrial Average. Tesla stock hasn't moved much, in absolute terms, since March. Shares were in the high $600s back then. They closed Tuesday at $665.71.