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 4.5, while the average ease score for reviewers in this category is 4.3. 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.

• 
• 3%
• Used substantial repetitive phrases

115 of the 4,004 total reviews for this product use substantial repetitive phrases between them. These reviewers have rated this product an average of 5.0 while reviews without substantial repetitive phrases rated this product an average of 4.8. 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.

• 
• 22%
• Substantial overlapping review history

882 of the 4,004 reviewers have substantial overlapping product review history. These reviewers have rated this product an average of 4.9 while the reviewers who have a more unique product review history rated this product an average of 4.8. 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 Overlapping Review History test.

• 100
• Reviews have been deleted

We discovered a total of 100 deleted Reviews for this product, with an average rating of 4.7. 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

• 
• 11%
• Created over 53 days

We counted 4,004 reviews for this product over the span of 3,079 days, an average of 1.3 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 6 or fewer reviews on any given day.

However, we see the following 53 days exceeding this threshold:

• 15 Reviews on Sep 25, 2015 (Avg. rating: 5.0)
• 15 Reviews on Jan 28, 2012 (Avg. rating: 4.5)
• 13 Reviews on Oct 7, 2015 (Avg. rating: 5.0)
• 12 Reviews on Feb 20, 2012 (Avg. rating: 4.8)
• 11 Reviews on Jan 21, 2012 (Avg. rating: 4.6)
• 11 Reviews on Feb 21, 2012 (Avg. rating: 4.5)
• 10 Reviews on Feb 23, 2012 (Avg. rating: 5.0)
• 10 Reviews on Feb 14, 2012 (Avg. rating: 4.9)
• 9 Reviews on Oct 1, 2011 (Avg. rating: 5.0)
• 9 Reviews on Feb 19, 2012 (Avg. rating: 5.0)
• 9 Reviews on Mar 26, 2015 (Avg. rating: 4.8)
• 9 Reviews on Aug 20, 2014 (Avg. rating: 4.8)
• 9 Reviews on Jan 23, 2012 (Avg. rating: 4.2)
• 9 Reviews on Feb 17, 2012 (Avg. rating: 4.1)
• 9 Reviews on Jan 22, 2012 (Avg. rating: 3.8)
• 8 Reviews on Mar 2, 2016 (Avg. rating: 5.0)
• 8 Reviews on Oct 2, 2014 (Avg. rating: 5.0)
• 8 Reviews on Feb 9, 2016 (Avg. rating: 5.0)
• 8 Reviews on Dec 28, 2012 (Avg. rating: 5.0)
• 8 Reviews on Dec 18, 2014 (Avg. rating: 5.0)
• 8 Reviews on Dec 11, 2014 (Avg. rating: 5.0)
• 8 Reviews on Aug 8, 2014 (Avg. rating: 4.9)
• 8 Reviews on Feb 15, 2012 (Avg. rating: 4.8)
• 8 Reviews on Nov 29, 2014 (Avg. rating: 4.8)
• 8 Reviews on Jan 14, 2013 (Avg. rating: 4.6)
• 8 Reviews on Jan 18, 2012 (Avg. rating: 4.6)
• 8 Reviews on Feb 11, 2012 (Avg. rating: 4.4)
• 8 Reviews on Jan 19, 2012 (Avg. rating: 4.3)
• 7 Reviews on Feb 25, 2012 (Avg. rating: 5.0)
• 7 Reviews on Jan 24, 2016 (Avg. rating: 5.0)
• 7 Reviews on Dec 31, 2012 (Avg. rating: 5.0)
• 7 Reviews on Jan 8, 2013 (Avg. rating: 5.0)
• 7 Reviews on Oct 22, 2015 (Avg. rating: 5.0)
• 7 Reviews on Jan 24, 2012 (Avg. rating: 5.0)
• 7 Reviews on Aug 29, 2014 (Avg. rating: 5.0)
• 7 Reviews on Sep 6, 2014 (Avg. rating: 5.0)
• 7 Reviews on Dec 4, 2014 (Avg. rating: 5.0)
• 7 Reviews on Nov 20, 2014 (Avg. rating: 5.0)
• 7 Reviews on Feb 22, 2014 (Avg. rating: 4.9)
• 7 Reviews on Dec 1, 2014 (Avg. rating: 4.9)
• 7 Reviews on Oct 1, 2014 (Avg. rating: 4.9)
• 7 Reviews on Dec 23, 2014 (Avg. rating: 4.9)
• 7 Reviews on Jan 2, 2015 (Avg. rating: 4.9)
• 7 Reviews on Aug 27, 2014 (Avg. rating: 4.9)
• 7 Reviews on Apr 23, 2014 (Avg. rating: 4.9)
• 7 Reviews on Dec 29, 2012 (Avg. rating: 4.9)
• 7 Reviews on Feb 27, 2016 (Avg. rating: 4.9)
• 7 Reviews on Nov 10, 2014 (Avg. rating: 4.7)
• 7 Reviews on Jan 30, 2012 (Avg. rating: 4.4)
• 7 Reviews on Mar 14, 2013 (Avg. rating: 4.4)
• 7 Reviews on Feb 22, 2012 (Avg. rating: 4.4)
• 7 Reviews on Oct 28, 2014 (Avg. rating: 4.3)
• 7 Reviews on Mar 11, 2012 (Avg. rating: 4.0)
Show All

In total, we found that 439 reviews were created on just 53 days. Although any days with a larger number of reviews than expected is suspicious, these reviews do not appear to have a significant impact on the overall rating.

Read more about our Rating Trend test.

Take-Back Reviewers

• 
• 28%
• have previously deleted reviews

1,118 of the 4,004 reviewers have had at least one of their past reviews for another product deleted. While this is more Take-Back Reviewers than we'd expect to see, it does not appear to have a significant impact on the overall rating.

Read more about our Suspicious Reviewers test.

• 
• 34%
• 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 6-15 Reviews: 33.9% (Avg. rating: 4.8)

In total, we found that 1359 reviewers (or 34%) 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.

• 
• 14%
• Unverified Purchases

572 of the 4,004 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.

• 
• 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.

Brand Repeaters

• 
• 19%
• Reviewed other products from this brand

778 of the 4,004 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.

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

• 
• 0%
• Admitted to receiving an incentive

2 of the 4,004 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. Check out our study showing that Incentivized Reviewers are much more likely to leave a positive review.