Star ratings can mislead shoppers and impact sales, UBC study shows

CBC News

· Posted: Apr 12, 2025 9:00 AM EDT | Last Updated: 8 minutes ago

If you're deciding betwixt 2 products, some rated a 3.5, but 1 shows the people with stars portion the different uses plain numbers, likelihood are you'll prime the 1 with stars.

That's the cardinal uncovering from a recent study by the University of B.C. Sauder School of Business, which reveals that consumers consistently overestimate ratings shown arsenic stars and underestimate the aforesaid values erstwhile shown arsenic numbers.

"Whenever I spot a prima rating, particularly if it's a fractional one, which leads to incomplete prima pictures similar 3.5 oregon 3.7, I instrumentality a infinitesimal to inquire myself, americium I being fooled?" said Deepak Sirwani, an adjunct prof astatine UBC Sauder and co-author of the study.

When a merchandise standing is shown utilizing stars, a people similar 3.5 is typically displayed arsenic 3 afloat stars followed by a half-filled 4th star. 

WATCH | How antithetic standing visuals tin impact purchaser perception: 

Visually, this creates the content of an incomplete image, says Sirwani.

"So we thin to circular up and implicit the incomplete representation with the ocular ratings," helium explained during an interrogation with CBC's On The Coast. 

In contrast, numbers punctual consumers to fixate connected the archetypal digit — a improvement known arsenic the "left-digit effect."

"We work from near to right, particularly successful Western civilization and a batch of different civilizations, truthful we absorption much connected 3 successful the fig 3.5 … and circular down."

That spread successful perception, according to the research, tin person a monolithic effect. 

Impact connected sales 

"When you amusement a merchandise utilizing a prima rating, your income mightiness triple compared to the aforesaid standing shown utilizing numbers," Sirwani said.

But the survey besides warns that prima ratings mightiness pb to inflated expectations — and eventually, disappointed customers.

"[Consumers] mightiness consciousness they were implicit promised and nether delivered truthful that whitethorn summation antagonistic reviews," the study's co-author said. 

Researchers urge utilizing "visually implicit stars" — ones that lone amusement a star's filled-in part, not its wide border — to minimize bias.

Vancouver-based retail strategist David Ian Gray called the findings "clever" and "unique."

"I don't deliberation it's thing we're consciously reasoning astir day-to-day," helium told CBC News. "But reviews are incredibly influential connected user behaviour, spending choices."

Gray says brands hosting their ain interior reviews mightiness see switching formats — though helium cautions that galore consumers look for third-party ratings to debar bias.

"There are a batch of websites with dubious reviews, perchance paid for," helium said. "Consumers are looking for objectivity."

Gray says studies specified arsenic UBC's tin marque radical much alert.

"I deliberation consumers, erstwhile they perceive astir this, are going to beryllium a small spot much conscious of however they're intuitively reacting, and possibly double-check their thinking."

WATCH | Marketplace investigates fake reviews: 

The researchers enactment the study's implications agelong acold beyond merchandise reviews, stating that akin ocular biases whitethorn interaction however radical construe artillery beingness connected a phone, substance gauges, fittingness trackers, and safety ratings connected vehicles, among different things. 

The survey is calling for manufacture standards and regulatory guidelines, not lone to level the playing tract betwixt retailers, but to guarantee consumers aren't being misled — adjacent accidentally.  

"Whether it's pictorial formats oregon numbers, ratings matter, and platforms should astir apt deliberation astir it much cautiously than they have," said Sirwani.