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 4.4, 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.

• 
• 39%
• 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:

• 6-15 words: 18.9% (Avg. rating: 4.5)
• 16-25 words: 19.7% (Avg. rating: 4.4)

In total, we found that 372 reviews (or 39%) are within an overrepresented word count group. These reviews have rated this product an average of 4.5, while all other reviews 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 Word Count Comparison test.

• 
• 25%
• Used substantial repetitive phrases

237 of the 965 total reviews for this product use substantial repetitive phrases between them. These reviewers have rated this product an average of 4.6 while reviews without substantial repetitive phrases 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 Phrase Repetition test.

• 
• 17%
• Created over 17 days

We counted 965 reviews for this product over the span of 643 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 17 days exceeding this threshold:

• 19 Reviews on Dec 27, 2018 (Avg. rating: 4.4)
• 13 Reviews on Dec 30, 2018 (Avg. rating: 4.6)
• 11 Reviews on Jan 13, 2019 (Avg. rating: 4.2)
• 10 Reviews on Jan 2, 2019 (Avg. rating: 4.6)
• 10 Reviews on Apr 8, 2019 (Avg. rating: 4.5)
• 10 Reviews on Mar 28, 2019 (Avg. rating: 4.2)
• 9 Reviews on Mar 8, 2019 (Avg. rating: 4.3)
• 8 Reviews on Mar 13, 2019 (Avg. rating: 4.9)
• 8 Reviews on Jan 4, 2019 (Avg. rating: 4.6)
• 8 Reviews on Jan 25, 2019 (Avg. rating: 4.6)
• 8 Reviews on Mar 24, 2019 (Avg. rating: 4.6)
• 8 Reviews on Feb 28, 2019 (Avg. rating: 4.5)
• 8 Reviews on Mar 7, 2019 (Avg. rating: 4.5)
• 8 Reviews on Mar 29, 2019 (Avg. rating: 4.3)
• 8 Reviews on Jan 20, 2019 (Avg. rating: 4.1)
• 8 Reviews on May 9, 2019 (Avg. rating: 4.0)
• 8 Reviews on Apr 24, 2019 (Avg. rating: 2.8)
Show All

In total, we found that 162 reviews were created on just 17 days. This is an excessively high number of reviews submitted on these high volume days.

Read more about our Rating Trend test.

• 
• 80%
• From reviewers with an overrepresented participation

We see the following 3 participation groups with a statistically significant greater concentration than what we'd expect to see:

• Reviewers with 1-5 Reviews: 23.1% (Avg. rating: 4.2)
• Reviewers with 6-15 Reviews: 37.3% (Avg. rating: 4.3)
• Reviewers with 16-30 Reviews: 19.9% (Avg. rating: 4.3)

In total, we found that 775 reviewers (or 80%) 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.

• 
• 22%
• Unverified Purchases

211 of the 965 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

• 
• 3%
• have only posted one review

26 of the 965 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

• 
• 5%
• have zero verified purchases

45 of the 965 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

• 
• 16%
• have previously deleted reviews

151 of the 965 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

• 
• 0%
• have posted all their reviews on a single day

4 of the 965 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.

• 
• 30%
• Substantial overlapping review history

291 of the 965 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.

• 
• 2%
• Admitted to receiving an incentive

22 of the 965 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.

• 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.