Finding Helpful Reviews on Amazon.com

Whether you're shopping for music or a camera, customer reviews at Amazon.com can provide insights and details about a product that you can't find anywhere else. But not all reviews left by Amazon shoppers are particularly helpful.

Now researchers at Temple University in Philadelphia, Pennsylvania have identified what sort of reviews beset help shoppers decide what to buy. The results of their study can help you sift out the most useful customer reviews.

The research found that what makes a review useful depends on the type of product it's for. The study divided products into two categories: search and experience.

Search products can be described in detail with technical specifications. You can compare digital cameras by their image resolution, screen size and optical zoom range. The study looked at three search products, a Canon PowerShot digital camera, a Motorola cell phone and an HP laser printer.

Evaluating items in the experience category involves more personal taste. Experience products for this study were a Nelly Furtado CD, a Sims video game and an Apple iPod.

The Most Helpful Reviews

For all products the study investigated, shoppers find lengthy reviews most helpful. Long reviews are especially useful for search products, where shoppers like detailed, factual descriptions.

With experience products, the number of stars that a review gives influences its helpfulness. Shoppers find extremely high or low product ratings, of five or one star, least useful.

The best information on music, games and movies comes from reviews accompanied by ratings of 2 to 4 stars. These reviews offer a balance of pros and cons.

For search items like computers and cameras, how helpful a review is doesn't relate to the number of stars the review gives.

To find out what makes a customer review helpful, the study tallied star ratings and word counts for over 1500 reviews of the six products at Amazon.com. These data were compared with the proportion of yes answers posted to the question "Was this review helpful?" that's attached to each customer review on the Amazon website. Close to two-thirds of the responses found the review helpful.