‘Like’ This Article Online? Your Friends Will Probably Approve, Too, Scientists Say

But surprisingly, an unfair negative reaction will not spur others to dislike the article. Instead, a thumbs-down view will soon be counteracted by thumbs up from other readers.

Those are the implications of new research looking at the behavior of thousands of people reading online comments, scientists reported Friday in the journal Science. A positive nudge, they said, can set off a bandwagon of approval.

“Hype can work,” said one of the researchers, Sinan K. Aral, a professor of information technology and marketing at the Massachusetts Institute of Technology, “and feed on itself as well.”

If people tend to herd together on popular opinions, that could call into question the reliability of “wisdom of the crowd” ratings on Web sites like Yelp or Amazon and perhaps provide marketers with hints on how to bring positive attention to their products.

“This is certainly a provocative study,” said Matthew O. Jackson, a professor of economics at Stanford who was not involved with the research. “It raises a lot of questions we need to answer.”

Besides Dr. Aral (who is also a scholar in residence at The New York Times research and development laboratory, working on unrelated projects), the researchers are from Hebrew University in Jerusalem and New York University.

They were interested in answering a question that long predates the iPhone and Justin Bieber: Is something popular because it is actually good, or is it popular just because it is popular?

To help answer that question, the researchers devised an experiment in which they could manipulate a small corner of the Internet: reader comments.

They collaborated with an unnamed Web site, the company did not want its involvement disclosed, on which users submit links to news articles. Readers can then comment on the articles, and they can also give up or down votes on individual comments. Each comment receives a rating calculated by subtracting negative votes from positive ones.

The experiment performed a subtle, random change on the ratings of comments submitted on the site over five months: right after each comment was made, it was given an arbitrary up or down vote, or — for a control group — left alone. Reflecting a tendency among the site’s users to provide positive feedback, about twice as many of these arbitrary initial votes were positive: 4,049 to 1,942.

The first person reading the comment was 32 percent more likely to give it an up vote if it had been already given a fake positive score. There was no change in the likelihood of subsequent negative votes. Over time, the comments with the artificial initial up vote ended with scores 25 percent higher than those in the control group.

“That is a significant change,” Dr. Aral said. “We saw how these very small signals of social influence snowballed into behaviors like herding.”

Meanwhile, comments that received an initial negative vote ended up with scores indistinguishable from those in the control group.

The Web site allows users to say whether they like or dislike other users, and the researchers found that a commenter’s friends were likely to correct the negative score while enemies did not find it worth their time to knock down a fake up vote.

The distortion of ratings through herding is not a novel concern. Reddit, a social news site that said it was not the one that participated in the study, similarly allows readers to vote comments up or down, but it also allows its moderators to hide those ratings for a certain amount of time. “Now a comment will more likely be voted on based on its merit and appeal to each user, rather than having its public perception influence its votes,” it explained when it unveiled the feature in April.

Duncan J. Watts, a scientist at Microsoft Research, said the overall findings fit with “cumulative advantage,” the idea that something that starts slightly more popular will build upon that popularity until it is far ahead of its competitors — and conversely, something that does not catch on will usually fade away whether or not it is good.

He cited the new crime novel “The Cuckoo’s Calling,” by Robert Galbraith, which received good reviews but tiny sales when it was released in April. When it was revealed that Galbraith was a pseudonym for J. K. Rowling, the book suddenly had the cumulative advantage conferred by the Harry Potter series and jumped to the top of best-seller lists.

“The biggest obstacle to success is just being noticed,” Dr. Watts said.

But opinions do not invariably follow popularity. In an earlier experiment by Dr. Watts, people listened to a list of songs ranked by popularity and were asked to rate them. But for some, the list was inverted — what they were told was the most popular song was actually the least popular.

The incorrect list did affect how listeners rated the songs — the good songs never achieved the same popularity as among listeners who were given the correct list, and the bad songs did better than they would have otherwise.

“But we also found, in a result that was somewhat consistent with the result here, that sometimes the songs were able to recover their sort of real ranking in spite of the manipulation,” Dr. Watts said. The listeners, he said, “in effect noticed that the song was better or worse than we had made it seem.”

Bucks Blog: You're Probably One of Two Kinds of Shoppers

Carl Richards

Carl Richards is a certified financial planner in Park City, Utah, and is the director of investor education at the BAM Alliance. His book, “The Behavior Gap,” was published this year. His sketches are archived on the Bucks blog.

It’s official: I’m not a shopper! It has been a long and lonely road to this point, but it feels good to finally discover the truth about myself.

Last summer I needed a new sport coat. My current one was 10 years old and looked it. I kept putting off buying a new one, because every time I go shopping it’s no fun. No fun for me and no fun for anyone who goes with me. My wife vows never to go with me again after just about every shopping trip. Luckily, she forgets the pain just enough since I need her help if I have any hope of looking presentable.

Based on anecdotal evidence, I’m guessing that some people find shopping fun, even (or especially) on Black Friday. I have even heard that people actually like to go out with friends for the specific purpose of shopping. Some people even plan vacations around the activity.

This has long been a puzzle for me. It’s not that I want to become a recreational shopper. I just want to make it a bit less painful for people to be around me when a situation requires a trip to the store.

After years of working on my problem, I think I have it figured out.

In an effort to simplify the issue, I’ve divided the world into two kinds of people: those who think shopping is fun and those that don’t. There’s only a problem when you don’t know which camp you belong to.

Shoppers enjoy options. I guess it’s fun for them to think about which shirt goes well with the sport coat they’re there to get. To nonshoppers, options just get in the way of getting stuff done. For them, shopping is not about entertainment, mixing and matching or assembling an evening ensemble (whatever that is).

It’s about the fastest way in and out of the store with the exact item you already know you need or want. This activity isn’t even the same thing as shopping. It deserves its own name, maybe purpose-driven-shopping, or even better “getting stuff.”

When you’re getting stuff, you know what you want. It was determined before you walked in the door. No need to even think about accessories. Now here’s what my clothes shopping looks like! Need a tie with that? Hmm, let me look at that list. Nope, it’s not there. A belt? No, it’s not on the list. Extended warranty? Not on the list.

Getting stuff requires research. You need to know what you want. If you’re a nonshopper, don’t go to the store to do that research, or if you do, don’t take a shopper with you. They will think they’re going on a fun activity, like a fourth-grade field trip. Since you’re at cross purposes, it can lead to conflict when you put on your game face in the parking lot. For you, this is not fun and games; it’s getting stuff done.

The Internet is a great place for research, and I suggest you call it that. When you’re approached by a shopper and they ask what you’re doing on the Gap Web site, tell them, “Research.” This will make it clear that this is not fun, and if they decide to help, there should be no expectation of fun.

Looking back on the arguments I’ve had over money with my wife, many of them involve silent drives home after shopping. So if my theory holds true, acknowledging that I’m a getting stuff person and my wife is a shopping person can end these arguments. The same could hold true for you.

How does this compare to your shopping experience? Do you fall into the category of “getting stuff” or “shopping?”