Is your online review actually helpful? Research finds a sweet spot
Five stars might catch your eye, but new University of Auckland research suggests it's how a review is written that decides whether readers find it useful.
Most people check reviews before they buy a book, pick a movie or book a service, and most of us give some reviews more weight than others. Researchers at the University of Auckland's Business School have tried to work out why.
Their answer is formality, but only up to a point.
What makes a review helpful
Dr Shohil Kishore and Associate Professor Laszlo Sajtos analysed more than 100,000 movie and book reviews on Amazon, Google and LibraryThing, a community book review site. They measured each review against the number of "helpful votes" it got from readers. The study is published in the European Journal of Marketing.
Formal writing, in the study's terms, is precise and clear, persuasive, and light on self-reference. Informal reviews read more like spoken conversation.
Readers rated more formal reviews as more helpful. But past a certain level of formality, perceived helpfulness started to fall.
"The key takeaway is that there's a sweet spot," Shohil says. "Being too informal online can make a review less useful to others, but being overly formal can have a similar effect."
Formality also had a stronger effect on helpfulness than two other writing features studied in past review research. Those are complexity, meaning the variety of words and sentence structures, and readability, meaning how hard the text is to process.
Not all platforms are equal
For movies, the researchers compared 67,560 Amazon reviews with 31,517 Google reviews of the same 94 films, including Jaws, Finding Nemo and The Matrix. For books, they compared 4,409 Amazon reviews with 3,462 LibraryThing reviews of the same 53 titles.
Google movie reviews were typically shorter, less formal and simpler than Amazon's.
Amazon reviews were already around the level of formality linked to greater helpfulness, so more formality added little. The findings suggest Google movie reviews and LibraryThing book reviews could benefit from being more formal.
Why it matters for business
Shohil says understanding what makes a review helpful matters for both platforms and sellers. Previous research found that Amazon books whose reviews had more helpful votes tended to sell better.
The study suggests the most useful reviews focus on objective content and clear description, and leave out personal details like who someone watched a movie with or where they read a book.
"Avoid too many personal details or first-person statements and concentrate on the book, movie, product or service itself," Laszlo says.
He sees a role for the platforms too. "Online platforms might also help by encouraging this approach when people write reviews, with prompts or real-time feedback that steer reviewers towards clear, broadly relevant information."
For businesses that rely on customer reviews, that points to the prompts they put in front of customers. Asking specific questions about the product or service is likely to produce reviews other buyers find more useful than a general "tell us about your experience".