image title

Posting Yelp reviews to Facebook changes their nature, ASU study shows

An ASU professor shows how Facebook makes reviews happier but less helpful.
March 7, 2017

W. P. Carey School of Business professor Yili Hong breaks ground by examining review text, which is harder to quantify

Before you spend your hard-earned cash on a restaurant dinner, you want to make sure it’ll be worth it, and online reviews have become a big part of deciding where to eat.

A quick check of an online-review platform can show you how thousands of other people rated the food and service of restaurants, which thrive on the feedback.

There has been a lot of research on online reviews, but an Arizona State University professor’s paper is breaking new ground by looking at the actual words that people use in their reviews. He and his colleaguesHong’s colleagues on the paper were Nina (Ni) Huang of the Fox School of Business, Temple University, and Gordon Burtch of the Carlson School of Management, University of Minnesota. The paper, “Social Network Integration and User Content Generation: Evidence from Natural Experiments,” was published in MIS Quarterly. found that when the online-review platform Yelp started allowing users to post simultaneously on Facebook, it changed their nature.

The result was a double-edged sword for the sites — more reviews, which Yelp wants, but more “emotional” language, which users say is less helpful, according to previous research. In other words, more quantity but less quality.

Yili Hong, an ASU assistant professor of information systems, found that online restaurant reviews became more emotional when they also showed up on Facebook.

“Online reviews help consumers make decisions about which products to purchase, and firms want to leverage that to advertise their products and have good word of mouth,” said Yili Hong, an assistant professor of information systems in the W. P. Carey School of Business.

“There is a long stream of research in our discipline looking at user-generated content, but one thing the research really hasn’t delved into is the textual aspects.”

That’s because it’s much more difficult to quantify words compared with counting the number of stars or words in a review.

Hong and his colleagues wanted to see how integrating with Facebook — where consumers’ reviews could be seen by their friends — would change their words.

“How will this affect people’s behavior in writing reviews? They don’t want to disagree with their friends,” Hong said.

The team had a natural control situation when Yelp integrated with Facebook in July 2009 and TripAdvisor integrated 15 months later, providing a window that the team examined. They then randomly selected nearly 4,000 restaurants in New York City, Los Angeles, Chicago, Philadelphia and Phoenix that were reviewed on both platforms from 2008 to 2012.

They used automated text-mining software to calculate the presence of words in threeAn example of a review with “emotional” words is “yummy shakes and malts … my favorite place.” Cognitive wording: “Worn-out place, trying to make it charming without really succeeding.” Negation: “Not a lot of parking … food is nothing special.” linguistic categories — emotional, cognitive and negation, or disagreeing, language — in reviews of the restaurants on both Yelp and TripAdvisor. Then they compared the wording.

They found that when reviewers knew that their Facebook friends would see their reviews, they used more emotional language — and more positive emotions — and less cognitive language. There also is a big decrease in “negation” words.

That’s not necessarily a good thing for the review sites, Hong said.

“If you’re very emotional, people will think you’re just coming to dump your emotions in the reviews as opposed to being logical,” he said.

One takeaway for review sites: Consider ways to encourage users to be more logical and less emotional when writing reviews.

Online reviews are a huge business, both for the platforms — which make money by selling ads based on number of views on the site — and the businesses that are reviewed. Hong has two other papers on user-generated content that were recently published in the journal Management Science. In one, he and his team measured how people could be persuaded to write online reviews. The best way? A combination of financial incentives and peer pressure — telling them how many of their peers had contributed reviews. In another study, he found that using push alerts to tell reviewers how many “likes” they had compared with other reviewers only prompted them to produce more if they were winning. Low-performing reviewers would slack off when they discovered they weren’t competitive in “likes.”

Analyzing the linguistic features of reviews is the next frontier of research as more sophisticated evaluation techniques are developed, Hong said.

“Nowadays people are thinking about tweets and other social-media things, and they want to look into the text to measure things,” he said.

“Maybe they will even be able to measure sarcasm one day.”

Mary Beth Faller

reporter , ASU Now


image title

ASU research applies Darwinian medicine to bird guts

Evolutionary medicine applies evolutionary theory to health and disease.
Studying bird health might uncover solutions for human health.
March 9, 2017

School of Life Sciences doctoral candidate Pierce Hutton says study of microbes could lead to solutions in human health

The stomach of a house finch might hold secrets to how humans absorb nutrients, age and deal with the omniprescence of nighttime light pollution.

Pierce Hutton, doctoral candidate in Arizona State University’s School of Life SciencesThe School of Life Sciences is part of the College of Liberal Arts and Sciences., is studying the gut microbiome — the cocktail of microbes in the stomach that help digest food and promote health — of house finches to answer these questions.

His research is funded by ASU’s Center for Evolution and Medicine. Evolutionary medicine, also called Darwinian medicine, is the application of modern evolutionary theory to understanding health and disease. The goal is to understand why people and animals get sick, not simply how they get sick.

Human and animal common denominators can be used to diagnose, treat and heal all species. Human and veterinary medicine are the same, if examined from an evolutionary medicine standpoint.

Two years ago, the Center for Evolution and Medicine Venture Fund was launched to finance research projects that connect evolutionary biology and topics relevant to medicine or public health. The fund is open to all ASU, Mayo Clinic faculty and students.

Hutton had questions that arose from work in the behavioral ecology lab. Working along with postdoc Mathieu Giraudeau, he studied four questions relating to the gut biome of house finches: What do carotenoids tell us about overall health? What is the effect of light pollution? What role does the gut play in aging? What role does microbe diversity play in health?

The males have bright red breasts. Those plumage colors are made by chemicals called carotenoids, which they get from their diet. The intestine is a gatekeeper, so to speak.

“We think the males might vary in how well they absorb the carotenoids,” Hutton said. “One thing that might be helping them absorb them is the gut microbiome. It’s beneficial for them to absorb them, because the plumage colors they have are evaluated by females when they’re selecting mates. It could be some microbes in the gut are helping them become sexier. We wanted to manipulate their diet and see if certain microbes get more abundant. That would tell us which ones are beneficial for uptaking those carotenoids.”

Carotenoids are also linked to health. They have important health benefits in the forms of antioxidants and immune stimulants.

“You could make some extensions to human health and biology by saying, ‘Well, if we know these microbes are beneficial for taking in these key nutrients, then it might be the same case for humans as well,’” Hutton said. “There’s the medicine angle.”

Humans have carotenoids in their bodies, and it changes their appearance too. If Caucasians eat an excessive amount of carrots, they will take on an orange hue.

Hutton and Giraudeau added carotenoids to the birds’ diet. “We did find a major effect,” he said. “’We think these microbes might be related to the uptick of those.”

A second ongoing study is looking at how light pollution affects humans and wild animals. How does living with light in our homes and outside at night affect intestinal health?

“Light pollution is a global epidemic, so we were looking at how it affects the gut microbiome,” Hutton said.

They put birds in separate rooms, one with a blue light (blue light is more disruptive to sleep than any other wavelength) that switched on at night.

Hutton is also trying to manipulate the rate of aging in house finches by regulating their gut microbiome.

DNA has strands of non-coding DNA on the ends called telomeres. They protect DNA from damage.

“As you age and as your cells divide, those end caps shorten over time,” Hutton said. “It opens up DNA to becoming damaged more quickly. There are enzymes we can target to regrow these end caps. We can essentially slow or reverse biological aging in a way. We can do this by up-regulating this enzyme that does that. ... Intestinal health and the microbiome might change as people age. It might be helpful for medicine to know how it’s aging, if it does age, those sorts of things.”

The fourth experiment looked at how the cleanliness of bird feeders affects microbiome in birds. Many people neglect to clean their backyard bird feeders, and so birds are defecating on and eating from the same surface.

“This means that both pathogenic and beneficial microbes might have an easier time colonizing new hosts,” Hutton said.

They put up bird feeders in the wild. During some periods they allowed the feeders to accumulate dirt, and other periods they cleaned them daily.

“We are expecting to see a rise in the diversity of their gut microbe community when the feeder was dirty relative to when it was clean, which might also include more pathogenic bacteria,” Hutton said. “This might connect to humans because many human populations eat under less cleanly conditions, which could lead to similar effects. It also might help us understand how the process of urbanization, and feeding wildlife, affects their gastrointestinal health.”


Researchers are studying house finches because human and animal common denominators can be used to diagnose, treat and heal all species, according to evolutionary medicine. Photo courtesy of Creative Commons. 

Scott Seckel

Reporter , ASU Now