• 
• 9%
• Substantial overlapping review history

272 of the 3,190 reviewers have substantial overlapping product review history. These reviewers have rated this product an average of 4.5 while the reviewers who have a more unique product review history rated this product an average of 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.

Read more about our Overlapping Review History test.

• 159
• Reviews have been deleted

We discovered a total of 159 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

Take-Back Reviewers

• 
• 47%
• have previously deleted reviews

1,489 of the 3,190 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, the discrepancy in ratings between the Take-Back Reviewers and reviewers who don't have any deleted reviews in their history isn't significant enough to rule out the possibility of it being due to random chance.

Read more about our Suspicious Reviewers 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 4.1. While this discrepancy is rather large, it is not quite large enough to rule out the possibility of it being due random chance.

• 
• 2%
• Created over 12 days

We counted 3,190 reviews for this product over the span of 3,738 days, an average of 0.9 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 5 or fewer reviews on any given day.

However, we see the following 12 days exceeding this threshold:

• 8 Reviews on Nov 5, 2019 (Avg. rating: 4.4)
• 7 Reviews on Jul 26, 2019 (Avg. rating: 4.7)
• 7 Reviews on Sep 23, 2019 (Avg. rating: 3.9)
• 7 Reviews on Jan 12, 2020 (Avg. rating: 3.7)
• 6 Reviews on Feb 14, 2015 (Avg. rating: 5.0)
• 6 Reviews on Mar 1, 2015 (Avg. rating: 4.8)
• 6 Reviews on Nov 5, 2013 (Avg. rating: 4.7)
• 6 Reviews on May 12, 2015 (Avg. rating: 4.5)
• 6 Reviews on Sep 13, 2019 (Avg. rating: 4.5)
• 6 Reviews on Jul 2, 2014 (Avg. rating: 4.3)
• 6 Reviews on Feb 19, 2015 (Avg. rating: 4.2)
• 6 Reviews on Jan 24, 2014 (Avg. rating: 3.7)
Show All

In total, we found that 77 reviews were created on just 12 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.

• 
• 5%
• Unverified Purchases

167 of the 3,190 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.

• 
• 23%
• 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: 22.9% (Avg. rating: 4.4)

In total, we found that 729 reviews (or 23%) 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.

• 
• 4%
• Used substantial repetitive phrases

116 of the 3,190 total reviews for this product use substantial repetitive phrases between them. 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 Phrase Repetition 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.

Brand Repeaters

• 
• 10%
• Reviewed other products from this brand

325 of the 3,190 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

We didn't detect any reviews that used language indicating they were incentivized.
Read more about our Incentivized Reviews test. Check out our study showing that Incentivized Reviewers are much more likely to leave a positive review.