I have an open question for the people who complain about the potential of advertising networks to track your behavior on the Internet: What is a better way?

Some might say that all behavioral targeting should simply be banned. But if you don’t think that showing Chevy ads to people looking for cars is equivalent to poisoning the peanut butter, we need a middle ground that explains to people what’s going on and lets them decide what is acceptable.

This is much harder than it sounds: Any one Web page you visit can have a dozen advertisements and invisible bits of code that each send information about you to different companies, each with different ways of using that data. The privacy policy of the site you are looking at — not that anyone reads privacy policies — can’t even try to explain this to you, because the site owner doesn’t even know what all of its advertisers are doing.

Joseph Turow

I’m coming to the conclusion that each advertisement on a page has to speak for itself. That’s implicit in the approach Google is taking for its new behavioral targeting system. It puts the phrase “Ads by Google” on all its advertisements. Click that link and you’ll get some limited information about Google’s targeting system and an ability to adjust some of the interests that Google is tracking.

But Google’s approach is presented in a way that glosses over what they are doing and discourages people from reading the disclosure and exercising control, says Joseph Turow, a marketing professor at the Annenberg School for Communication of the University of Pennsylvania.

Mr. Turow has developed a plan that is simpler and more comprehensive: Put an icon on each ad that signifies that the ad collects or uses information about users. If you click the icon, you will go to what he calls a “privacy dashboard” that will let you understand exactly what information was used to choose that ad for you. And you’ll have the opportunity to edit the information or opt out of having any targeting done at all.

“I don’t think ‘Ads by Google’ is enough,'” he said. “The problem with the whole rhetoric Google is using is that it is designed to stop you from wanting to learn more and do something.”

In his mockup, Mr. Turow’s icon has a T for targeting and a question mark. I would propose a bull’s-eye or maybe some sort of creepy eyeball.

What I like about the idea of an icon is that users can learn which ads collect data without having to do anything other than surf the way they normally would. When they do get curious, you can click on the icon and learn more.

I asked Nicole Wong, the deputy general counsel of Google who looks after privacy issues, about Mr. Turow’s concept. She defended the phrase “Ads by Google” on the grounds of simplicity. Anything more risks confusing users.

“I wonder, would the user really understand what a behaviorally targeted ad is compared to a contextual ad?” she said, saying the company is open to changing the phrasing of the text of its notice.

The information that Google shows to people who click on the link on these ads is also similar to, but more limited than, what Mr. Turow proposes.

Mr. Turow’s dashboard is meant to explain exactly why you are seeing a particular ad. You will see what part of it was customized — the product, the price, the image and so on. You will also see the data used — your surfing habits, outside data vendors, inferences from your I.P. address, etc. You can click to learn more specifics about exactly where the data came from and to delete or modify the information used about you.

Google doesn’t tell you why you saw a particular ad, nor does it promise to tell you everything it knows about you. But it is showing you more than any other major ad network has done before: You can see which of 600 categories it infers you might be interested in based on what sites (that show Google ads) you visited in the past. It lets you add and delete items from its list of interests.

Ms. Wong said Google is trying “to give meaningful information the user can make decisions on but not to bury them.” She added, “Too much text, too many choices, becomes overwhelming.”

In fact, most people in the Internet advertising business think that even Google is going too far. They say that there is no evidence that many users would actually want that much information about their browsing history or have any use for actually editing the profile used to show them ads. After all, few people on the Internet customize much of anything.

Mr. Turow agrees that most people will not use this dashboard most of the time, but they will be very glad that it is there when they need it.

“When people begin to smell a rat with regard to their reputation or they feel they are being discriminated against, they will use it,” he said.

I agree. As a journalist, I’ve learned that specifics can communicate much better and faster than the over-broad language of lawyers. If a company puts its cards down and shows me everything it knows about me, that’s really the best way to decide whether what it is doing is too creepy.

I’m not concerned that most people won’t bother doing all this; some will, and they’ll tell everyone else. Only a handful of people read all the specs and reviews for digital cameras; the rest of us ask our geeky friends what to buy.

Mr. Turow also points out that simply forcing companies to be more transparent about the sort of data they collect, visible to activists and reporters as well as customers, will be a check on their behavior.

“When companies realize you have the ability to see what they are doing, they treat you better,” he said.