• 
• 14%
• Created over 18 days

We counted 1,580 reviews for this product over the span of 725 days, an average of 2.2 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 8 or fewer reviews on any given day.

However, we see the following 18 days exceeding this threshold:

• 29 Reviews on Jul 18, 2017 (Avg. rating: 4.5)
• 18 Reviews on Aug 21, 2017 (Avg. rating: 4.3)
• 15 Reviews on Jul 19, 2017 (Avg. rating: 3.9)
• 14 Reviews on Jun 15, 2017 (Avg. rating: 4.3)
• 12 Reviews on Sep 15, 2017 (Avg. rating: 4.3)
• 11 Reviews on Aug 14, 2017 (Avg. rating: 4.9)
• 11 Reviews on Aug 22, 2017 (Avg. rating: 4.1)
• 11 Reviews on Jun 10, 2017 (Avg. rating: 4.0)
• 10 Reviews on Jul 22, 2017 (Avg. rating: 5.0)
• 10 Reviews on Aug 3, 2017 (Avg. rating: 4.8)
• 10 Reviews on Aug 17, 2017 (Avg. rating: 4.6)
• 10 Reviews on Aug 23, 2017 (Avg. rating: 4.3)
• 10 Reviews on Jun 20, 2017 (Avg. rating: 4.1)
• 10 Reviews on Aug 2, 2018 (Avg. rating: 4.1)
• 10 Reviews on Sep 13, 2017 (Avg. rating: 3.9)
• 9 Reviews on Jun 26, 2017 (Avg. rating: 4.8)
• 9 Reviews on May 21, 2017 (Avg. rating: 4.6)
• 9 Reviews on Aug 24, 2017 (Avg. rating: 4.4)
Show All

In total, we found that 218 reviews were created on just 18 days. The reviews on these high volume days have rated this product an average of 4.4 while reviews from other days have rated this product an average of 4.1. 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.

• 
• 61%
• 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 2 groups with a statistically significant greater concentration than what we'd expect to see:

• 16-25 words: 28.1% (Avg. rating: 4.3)
• 26-40 words: 33.4% (Avg. rating: 4.2)

In total, we found that 971 reviews (or 61%) 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 4.0. 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.

• 
• 22%
• Used substantial repetitive phrases

341 of the 1,580 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 4.0. 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.

One-Hit Wonders

• 
• 12%
• have only posted one review

185 of the 1,580 reviewers have only reviewed this product. While this is more One-Hit Wonders 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.

• 
• 42%
• 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 1-5 Reviews: 42.3% (Avg. rating: 4.0)

In total, we found that 668 reviewers (or 43%) 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.

• 
• 3%
• Unverified Purchases

48 of the 1,580 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.

• 
• 1%
• Substantial overlapping review history

15 of the 1,580 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.

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 4.2.

Brand Repeaters

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

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.

• 0
• Reviews have been deleted

We have not discovered any deleted reviews for this product.

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.