• 55
• Reviews have been deleted

We discovered a total of 55 deleted Reviews for this product, with an average rating of 4.9. 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

• 
• 49%
• Unverified Purchases

27 of the 55 total reviews for this product are unverified purchases. The unverified purchasers have rated this product an average of 4.7 while the verified purchasers 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.

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.

One-Hit Wonders

• 
• 18%
• have only posted one review

10 of the 55 reviewers have only reviewed this product. While this is more One-Hit Wonders than we'd expect to see, the discrepancy in ratings between the One-Hit Wonders and reviewers who have posted more than one review isn't significant enough to rule out the possibility of it being due to random chance.

Never-Verified Reviewers

• 
• 16%
• have zero verified purchases

9 of the 55 reviewers have never written a verified purchase review. The Never-Verified Reviewers have rated this product an average of 5.0 while the reviewers who have written at least one verified purchase review rated this product an average of 4.2. 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

• 
• 31%
• have previously deleted reviews

17 of the 55 reviewers have had at least one of their past reviews for another product deleted. This is an excessively large percentage of Take-Back Reviewers which may indicate unnatural reviews.

Single-Day Reviewers

• 
• 20%
• have posted all their reviews on a single day

11 of the 55 reviewers have written multiple reviews but posted all of them on a single day. While this is more Single-Day 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.

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

• 
• 20%
• Admitted to receiving an incentive

11 of the 55 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.

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 4.4. While this discrepancy is rather large, it is not quite large enough to rule out the possibility of it being due random chance.

• 
• 15%
• Used substantial repetitive phrases

8 of the 55 total reviews for this product use substantial repetitive phrases between them. This is an excessively large percentage which may indicate unnatural reviews.

Read more about our Phrase Repetition test.

• 
• 55%
• From reviewers with an overrepresented participation

We see the following 2 participation groups with a statistically significant greater concentration than what we'd expect to see:

• Reviewers with 1-5 Reviews: 27.3% (Avg. rating: 4.9)
• Reviewers with 6-15 Reviews: 27.3% (Avg. rating: 4.0)

In total, we found that 30 reviewers (or 55%) are within an overrepresented participation group. This is an excessively high number of reviewers in overrepresented participation groups.

Read more about our Reviewer Participation test.

• 
• 0%
• Created over 5 days

We counted 55 reviews for this product over the span of 369 days, an average of 0.1 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 5 days exceeding this threshold:

• 7 Reviews on Sep 29, 2016 (Avg. rating: 4.7)
• 5 Reviews on Jun 12, 2016 (Avg. rating: 5.0)
• 5 Reviews on Jun 13, 2016 (Avg. rating: 5.0)
• 5 Reviews on Sep 30, 2016 (Avg. rating: 5.0)
• 5 Reviews on Sep 23, 2016 (Avg. rating: 4.4)

In total, we found that 0 reviews were created on just 5 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.

• 
• 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.

• 
• 29%
• Substantial overlapping review history

16 of the 55 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.

Brand Repeaters

We didn't detect a substantial amount of Brand Repeaters.