Researchers say star rating on sites such as Amazon not to be trusted
Internet shoppers should not trust star ratings on websites such as Amazon, according to an academic study.
Researchers analysed more than 300,000 ratings of 1,300 products on Amazon and found that the number of stars awarded did not correlate with the objective quality of the item for sale.
The study focused on products that were easy to judge objectively, such as air-conditioning units and car batteries. It found that customer ratings often differed from professional reviews conducted in independent laboratories. It also found that consumers were more likely to give a positive review to more expensive products and brands they knew, irrespective of quality.
Researchers from the University of Colorado compared star ratings on Amazon to star ratings by Consumer Reports, the US magazine that tests products as its in-house laboratory and survey centre.
The study found that customers give a better score to a more expensive product or premium brand than a cheaper alternative even when they had the same Consumer Reports score.
“The combined influence of price and brand image on the average rating is much larger than the effect of objective quality as measured by Consumer Reports, explaining more than four times as much variance” the research published in the Journal of Consumer Research said.