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 4.2. 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.

• 
• 72%
• 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:

• 0-5 words: 40.3% (Avg. rating: 4.8)
• 6-15 words: 32.1% (Avg. rating: 4.7)

In total, we found that 7,243 reviews (or 72%) are within an overrepresented word count group. These reviews have rated this product an average of 4.8, while all other reviews have rated this product an average of 4.4. 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.

• 
• 18%
• Used substantial repetitive phrases

1,801 of the 10,000 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 4.6. 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.

• 
• 8%
• Created over 24 days

We counted 10,000 reviews for this product over the span of 695 days, an average of 14.4 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 28 or fewer reviews on any given day.

However, we see the following 24 days exceeding this threshold:

• 46 Reviews on Aug 5, 2019 (Avg. rating: 4.8)
• 38 Reviews on Aug 9, 2019 (Avg. rating: 4.8)
• 38 Reviews on Aug 1, 2019 (Avg. rating: 4.7)
• 38 Reviews on Sep 27, 2019 (Avg. rating: 4.7)
• 38 Reviews on Aug 6, 2019 (Avg. rating: 4.6)
• 37 Reviews on Aug 2, 2019 (Avg. rating: 4.9)
• 37 Reviews on Jul 20, 2019 (Avg. rating: 4.8)
• 35 Reviews on Mar 14, 2019 (Avg. rating: 4.7)
• 35 Reviews on Aug 12, 2019 (Avg. rating: 4.7)
• 34 Reviews on Jun 8, 2019 (Avg. rating: 4.8)
• 32 Reviews on Dec 28, 2018 (Avg. rating: 4.8)
• 32 Reviews on Aug 7, 2019 (Avg. rating: 4.6)
• 32 Reviews on Jul 19, 2019 (Avg. rating: 4.6)
• 31 Reviews on Aug 11, 2019 (Avg. rating: 4.7)
• 31 Reviews on Dec 21, 2018 (Avg. rating: 4.5)
• 31 Reviews on Jan 13, 2019 (Avg. rating: 4.4)
• 30 Reviews on Jan 4, 2019 (Avg. rating: 5.0)
• 30 Reviews on Jul 18, 2019 (Avg. rating: 4.9)
• 30 Reviews on Jul 22, 2019 (Avg. rating: 4.7)
• 30 Reviews on May 3, 2019 (Avg. rating: 4.6)
• 30 Reviews on Dec 26, 2018 (Avg. rating: 4.5)
• 29 Reviews on Aug 30, 2019 (Avg. rating: 4.9)
• 29 Reviews on Jul 25, 2019 (Avg. rating: 4.8)
• 29 Reviews on Jan 17, 2019 (Avg. rating: 4.7)
Show All

In total, we found that 802 reviews were created on just 24 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.

• 
• 77%
• 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: 33.5% (Avg. rating: 4.6)
• Reviewers with 6-15 Reviews: 44.0% (Avg. rating: 4.7)

In total, we found that 7748 reviewers (or 77%) 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.

• 
• 2%
• Unverified Purchases

157 of the 10,000 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.

One-Hit Wonders

• 
• 4%
• have only posted one review

446 of the 10,000 reviewers have only reviewed this product. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.

Never-Verified Reviewers

• 
• 0%
• have zero verified purchases

27 of the 10,000 reviewers have never written a verified purchase review. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.

Take-Back Reviewers

• 
• 6%
• have previously deleted reviews

637 of the 10,000 reviewers have had at least one of their past reviews for another product deleted. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.

Single-Day Reviewers

• 
• 5%
• have posted all their reviews on a single day

464 of the 10,000 reviewers have written multiple reviews but posted all of them on a single day. 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 Suspicious Reviewers test.

• 
• 16%
• Substantial overlapping review history

1,550 of the 10,000 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.

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.