• 292
• Reviews have been deleted

We discovered a total of 292 deleted Reviews for this product, with an average rating of 4.3. 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

One-Hit Wonders

• 
• 3%
• have only posted one review

87 of the 2,539 reviewers have only reviewed this product. The One-Hit Wonders have rated this product an average of 2.9 while the reviewers who have posted more than one review 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.

Take-Back Reviewers

• 
• 42%
• have previously deleted reviews

1,066 of the 2,539 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 3.7. 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%
• 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: 23.1% (Avg. rating: 4.2)

In total, we found that 587 reviews (or 23%) are within an overrepresented word count group. These reviews have rated this product an average of 4.2, while all other reviews 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.

Read more about our Word Count Comparison test.

• 
• 3%
• Used substantial repetitive phrases

82 of the 2,539 total reviews for this product use substantial repetitive phrases between them. These reviewers have rated this product an average of 4.8 while reviews without substantial repetitive phrases 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 Phrase Repetition test.

• 
• 11%
• Substantial overlapping review history

290 of the 2,539 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 3.8. 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.

• 
• 13%
• Created over 21 days

We counted 2,539 reviews for this product over the span of 1,664 days, an average of 1.5 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 7 or fewer reviews on any given day.

However, we see the following 21 days exceeding this threshold:

• 68 Reviews on Jan 4, 2018 (Avg. rating: 4.6)
• 45 Reviews on Apr 17, 2018 (Avg. rating: 4.8)
• 32 Reviews on May 2, 2018 (Avg. rating: 4.8)
• 29 Reviews on Jan 5, 2018 (Avg. rating: 4.7)
• 18 Reviews on Apr 18, 2018 (Avg. rating: 4.4)
• 12 Reviews on Dec 26, 2017 (Avg. rating: 1.4)
• 10 Reviews on Apr 25, 2017 (Avg. rating: 4.5)
• 10 Reviews on May 3, 2018 (Avg. rating: 4.5)
• 9 Reviews on May 23, 2017 (Avg. rating: 4.0)
• 9 Reviews on Dec 30, 2017 (Avg. rating: 3.1)
• 9 Reviews on Dec 22, 2017 (Avg. rating: 2.7)
• 9 Reviews on Dec 12, 2017 (Avg. rating: 1.7)
• 9 Reviews on Dec 17, 2017 (Avg. rating: 1.6)
• 8 Reviews on Jun 12, 2017 (Avg. rating: 4.4)
• 8 Reviews on Jun 20, 2017 (Avg. rating: 4.4)
• 8 Reviews on Jan 2, 2018 (Avg. rating: 3.4)
• 8 Reviews on Feb 20, 2017 (Avg. rating: 3.0)
• 8 Reviews on Jun 3, 2017 (Avg. rating: 2.4)
• 8 Reviews on Jan 6, 2018 (Avg. rating: 2.3)
• 8 Reviews on Dec 16, 2017 (Avg. rating: 1.6)
• 8 Reviews on Dec 27, 2017 (Avg. rating: 1.4)
Show All

In total, we found that 333 reviews were created on just 21 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.

• 
• 5%
• Unverified Purchases

122 of the 2,539 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%
• 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 4.1, while the average ease score for reviewers in this category is 4.1.

Brand Repeaters

• 
• 13%
• Reviewed other products from this brand

336 of the 2,539 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

1 of the 2,539 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.