• 1,425
• Reviews have been deleted

We discovered a total of 1,425 deleted Reviews for this product, with an average rating of 4.5. Even though deleted reviews don't affect the average rating, the fact that action was taken to delete reviews raises some red flags about the integrity of the reviews for the product as whole.

There are a few limitations to keep in mind regarding the Deleted Reviews test:

1. We don't have a magic ability to collect every single deleted review; we can only identify reviews as deleted if we collect them on one date and then notice they are no longer visible on a subsequent date.
2. We have no information on reviews that were never published in the first place.
3. We also don't know why these reviews were removed. It could be action from the platform, personal decision by the review author, part of an entire account closure, even some data error on our part, etc.

Read more about our Deleted Reviews test.

Show distribution of deleted reviews

• 
• 40%
• Created over 16 days

We counted 188 reviews for this product over the span of 1,077 days, an average of 0.2 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 3 or fewer reviews on any given day.

However, we see the following 16 days exceeding this threshold:

• 7 Reviews on May 9, 2016 (Avg. rating: 4.6)
• 7 Reviews on Apr 24, 2016 (Avg. rating: 4.3)
• 6 Reviews on May 3, 2016 (Avg. rating: 4.8)
• 5 Reviews on May 10, 2016 (Avg. rating: 4.0)
• 5 Reviews on May 24, 2016 (Avg. rating: 4.0)
• 5 Reviews on May 26, 2016 (Avg. rating: 4.0)
• 5 Reviews on May 5, 2016 (Avg. rating: 3.8)
• 4 Reviews on Apr 23, 2016 (Avg. rating: 5.0)
• 4 Reviews on Apr 26, 2016 (Avg. rating: 4.8)
• 4 Reviews on Apr 28, 2016 (Avg. rating: 4.8)
• 4 Reviews on May 16, 2016 (Avg. rating: 4.3)
• 4 Reviews on Apr 21, 2016 (Avg. rating: 4.0)
• 4 Reviews on May 11, 2016 (Avg. rating: 4.0)
• 4 Reviews on May 2, 2016 (Avg. rating: 3.8)
• 4 Reviews on May 13, 2016 (Avg. rating: 3.5)
• 4 Reviews on Jul 17, 2016 (Avg. rating: 3.3)
Show All

In total, we found that 76 reviews were created on just 16 days. The reviews on these high volume days have rated this product an average of 4.2 while reviews from other days 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 Rating Trend test.

• 
• 54%
• Unverified Purchases

102 of the 188 total reviews for this product are unverified purchases. The unverified purchasers have rated this product an average of 4.2 while the verified purchasers have rated this product an average of 3.8. 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.

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.

Take-Back Reviewers

• 
• 71%
• have previously deleted reviews

134 of the 188 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 4.1 while the reviewers who don't have any deleted reviews in their history have rated this product an average of 3.6. 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.

• 
• 23%
• Used substantial repetitive phrases

43 of the 188 total reviews for this product use substantial repetitive phrases between them. These reviewers have rated this product an average of 4.5 while reviews without substantial repetitive phrases rated this product an average of 3.8. 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.

• 
• 31%
• Substantial overlapping review history

58 of the 188 reviewers have substantial overlapping product review history. These reviewers have rated this product an average of 4.3 while the reviewers who have a more unique product review history 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 Overlapping Review History test.

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

• 
• 16%
• Admitted to receiving an incentive

30 of the 188 total reviews for this product admitted to receiving a free or discounted product in exchange for a review. While we could not find a statistically significant difference between the average rating of incentivized reviews and non-incentivized reviews, the presences of at least one incentivized review indicates that there may be more, since not all reviewers will disclose that they had received an incentive to post a review.

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

• 
• 0%
• Have an overrepresented word count

We didn't find any review word count groups that had a statistically significant greater concentration than what we'd expect to see in this category.
Read more about our Word Count Comparison test.

• 
• 0%
• From reviewers with an overrepresented participation

We didn't find any participation groups that had a statistically significant greater concentration than what we'd expect to see in this category.
Read more about our Reviewer Participation 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 4.2, while the average ease score for reviewers in this category is 4.3.

Brand Repeaters

• 
• 22%
• Reviewed other products from this brand

41 of the 188 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.