GEOFF BENNETT: When it comes to travel and especially booking airfare, there are new concerns around how artificial intelligence might be used to set prices.

AMNA NAWAZ: The worry comes after Delta Air Lines announced it was using A.I.

to help adjust prices on some of its flights.

In this report that first ran on our digital platforms, producer Tim McPhillips takes a look at how travelers should approach buying plane tickets and how all consumers can help guard themselves against A.I.-driven custom pricing.

TIM MCPHILLIPS: You may have heard that Delta is using artificial intelligence to help set some airfare prices.

That sparked fears that the airline could create a custom price for you, using your data to find how much you would be willing to pay for a ticket.

But while Delta says they aren't doing that, they are using A.I.

to help them adjust prices in response to market forces faster than humans can.

Here are three things to know if you're booking airfare now and whether custom pricing could impact you in the future.

One, if you're booking airfare now, the same old adages apply to find the best fare.

Delta is testing A.I.

to help set prices on limited flights, about 3 percent of fares for now, moving to 20 percent by the end of the year.

But while A.I.

might help prices move up and down faster, we currently all still see the same price.

So, for a better deal, it's still a good idea to be flexible, which may mean flying on lower-demand days, like Tuesday, Wednesday, or Saturday.

Consider alternate airports in the areas you are traveling to and from.

Use flight comparison tools like Google Flights to easily compare cities, dates, and airlines.

If you're flying round-trip, check to see if two one-way tickets are cheaper than a round-trip booking.

And consider budget airlines or basic economy tickets on mainline carriers.

But if you do so, just be sure to pack light to avoid extra fees.

Two, much of the fear sparked by Delta's announcement comes from what Delta or any other airline or other company, for that matter, could do.

JAY ZAGORSKY, Boston University Questrom: What I do hear from many businesses, they're saying that, by using A.I.

models, they're able to get both higher revenue and higher profits.

And that tells me A.I.

is effective.

TIM MCPHILLIPS: Jay Zagorsky is a professor at the Questrom School of Business at Boston University.

JAY ZAGORSKY: We don't have any idea right now which companies are using A.I.

and which are not.

And this is the problem I have with A.I.

pricing.

It's not transparent and it can be taking advantage of people who are not financially sophisticated.

TIM MCPHILLIPS: A.I.

could eventually help you get a better deal.

JAY ZAGORSKY: A.I.

can actually come up with custom prices.

You can see a price on the shelf, and if you attempt to linger in that aisle a little bit, we can send you a custom ad, hey, 10 cents off or 5 percent if you buy two of them right now.

TIM MCPHILLIPS: But there is real worry that A.I.

could be used to harness vast amounts of data to build a consumer profile on you and charge you a custom price based on that information.

And that means that your personalized price could be lower or much higher than, say, what someone else looking at that exact same product sees.

Here's Reuters transportation reporter David Shepardson speaking to Ali Rogin on "PBS News Weekend."

DAVID SHEPARDSON, Reuters: The example that a couple members of Congress made last week was if someone went and looked at an obituary, right, and then went to an airline pricing Web site, would they be more likely to pay more money because presumably they were looking at an obituary of a family friend or so on?

TIM MCPHILLIPS: Three, so how can you guard against A.I.-driven custom pricing?

JAY ZAGORSKY: How do you defeat A.I.?

Well, A.I.

runs on data.

The less data you give A.I., the worse its prediction.

TIM MCPHILLIPS: Professor Zagorsky recommends a few things.

Use cash for in-store purchases when you can.

That won't leave a data trail of what you're interested in or how much you have spent.

Clear your cache.

According to the FTC, new A.I.

programs could use your browsing history to help set prices for products.

And, third, consider using a VPN, which hides your I.P.

address and encrypts your Internet traffic.

If, like myself, you're worried that using cash might hurt your credit card rewards-funded vacation: JAY ZAGORSKY: My response is pretty straightforward.

Those rewards, those points, they're getting you some benefit, but you have to pay for those benefits.

And how are you going to be paying for those benefits in the future?

One way is by giving A.I.

information, so it can charge you the maximum price.

TIM MCPHILLIPS: And for those of us who grew up on the Internet and may have given up on privacy to participate in the digital world: JAY ZAGORSKY: Yes, you don't think there's any downside for you losing your privacy in this digital world.

But I'm here to tell you that customized pricing is going to cost you a lot.

And by maintaining your privacy, even if you're doing absolutely nothing wrong, you're probably going to pay less money in the future.

TIM MCPHILLIPS: For PBS News, I'm Tim McPhillips.