One-Hit Wonders

• 
• 10%
• have only posted one review

31 of the 321 reviewers have only reviewed this product. The One-Hit Wonders have rated this product an average of 3.2 while the reviewers who have posted more than one review have rated this product an average of 4.0. Based on our statistical modeling, the discrepancy in average rating between these two groups is significant enough to believe that the difference is not due to random chance, and may indicate that there are unnatural reviews.

Never-Verified Reviewers

• 
• 2%
• have zero verified purchases

8 of the 321 reviewers have never written a verified purchase review. The Never-Verified Reviewers have rated this product an average of 3.0 while the reviewers who have written at least one verified purchase review rated this product an average of 4.0. Based on our statistical modeling, the discrepancy in average rating between these two groups is significant enough to believe that the difference is not due to random chance, and may indicate that there are unnatural reviews.

Take-Back Reviewers

• 
• 7%
• have previously deleted reviews

23 of the 321 reviewers have had at least one of their past reviews for another product deleted. The Take-Back Reviewers have rated this product an average of 4.4 while the reviewers who don't have any deleted reviews in their history have rated this product an average of 3.9. Based on our statistical modeling, the discrepancy in average rating between these two groups is significant enough to believe that the difference is not due to random chance, and may indicate that there are unnatural reviews.

Read more about our Suspicious Reviewers test.

• 
• 4%
• Used substantial repetitive phrases

13 of the 321 total reviews for this product use substantial repetitive phrases between them. These reviewers have rated this product an average of 3.1 while reviews without substantial repetitive phrases rated this product an average of 4.0. Based on our statistical modeling, the discrepancy in average rating between these two groups is significant enough to believe that the difference is not due to random chance, and may indicate that there are unnatural reviews.

Read more about our Phrase Repetition test.

• 
• 42%
• From reviewers with an overrepresented participation

We see the following 1 participation group with a statistically significant greater concentration than what we'd expect to see:

• Reviewers with 1-5 reviews: 42.4% (Avg. rating: 3.6)

In total, we found that 136 reviewers (or 42%) are within an overrepresented participation group. While this is more reviews from overrepresented participation groups than we'd expect to see, these reviews do not appear to have a significant impact on the overall rating.

Read more about our Reviewer Participation test.

• 
• 3%
• Created over 2 days

We counted 321 reviews for this product over the span of 565 days, an average of 0.6 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 4 or fewer reviews on any given day.

However, we see the following 2 days exceeding this threshold:

• 6 reviews on May 26, 2017 (Avg. rating: 4.3)
• 5 reviews on Mar 28, 2017 (Avg. rating: 3.4)

In total, we found that 11 reviews were created on just 2 days. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.

Read more about our Rating Trend test.

• 
• 13%
• Unverified Purchases

41 of the 321 total reviews for this product are unverified purchases. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.

Unverified purchases may be the result of Kindle Unlimited readers, buyers who didn't pay full price, or reviewers who did not purchase the product at Amazon. Read more about our Unverified Purchases test.

• 
• 27%
• Have an overrepresented word count

In the graph above, we can see the distribution of review word counts for this product and the expected distribution for this category. We see the following 1 group with a statistically significant greater concentration than what we'd expect to see:

• 6-15 words: 27.4% (Avg. rating: 3.7)

In total, we found that 88 reviews (or 27%) are within an overrepresented word count group. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.

Read more about our Word Count Comparison test.

• 
• 5%
• Substantial overlapping review history

17 of the 321 reviewers have substantial overlapping product review history. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.

Read more about our Overlapping Review History test.

The ease score is the average rating for all reviews that a given reviewer submits. The average ease score for reviewers of this product is 4.1, while the average ease score for reviewers in this category is 4.4.

Brand Repeaters

• 
• 4%
• Reviewed other products from this brand

13 of the 321 reviewers have reviewed other products for this brand. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.

Read more about our Brand Repeats test.

We examined the average net helpfulness score of negative reviews against the average net helpfulness score of positive reviews. The net helpfulness score is the number of times a review has been marked as helpful minus the number of times a review has been marked as unhelpful. We could not find any statistically significant difference in average net helpfulness score between the negative reviews and positive reviews.

On Oct 3, 2016, Amazon prohibited incentivized reviews, however we still test for them since there are still millions in our dataset.

• 
• 1%
• Admitted to receiving an incentive

4 of the 321 total reviews for this product admitted to receiving a free or discounted product in exchange for a review. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.

Read more about our Incentivized Reviews test, or check out our study showing that Incentivized Reviewers are much more likely to leave a positive review.