• 
• 13%
• Created over 21 days

We counted 1,041 reviews for this product over the span of 1,798 days, an average of 0.6 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 4 or fewer reviews on any given day.

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

• 14 Reviews on Feb 20, 2015 (Avg. rating: 4.6)
• 8 Reviews on Mar 1, 2015 (Avg. rating: 4.6)
• 7 Reviews on Feb 5, 2015 (Avg. rating: 5.0)
• 7 Reviews on Mar 24, 2015 (Avg. rating: 5.0)
• 7 Reviews on Jan 20, 2016 (Avg. rating: 4.7)
• 7 Reviews on Feb 8, 2015 (Avg. rating: 4.3)
• 6 Reviews on Feb 14, 2015 (Avg. rating: 5.0)
• 6 Reviews on Feb 7, 2015 (Avg. rating: 4.8)
• 6 Reviews on Feb 24, 2015 (Avg. rating: 4.8)
• 6 Reviews on Feb 26, 2015 (Avg. rating: 4.8)
• 6 Reviews on Sep 16, 2015 (Avg. rating: 4.8)
• 6 Reviews on Mar 8, 2015 (Avg. rating: 4.5)
• 6 Reviews on Sep 20, 2017 (Avg. rating: 4.2)
• 5 Reviews on Feb 23, 2015 (Avg. rating: 5.0)
• 5 Reviews on Feb 6, 2015 (Avg. rating: 4.8)
• 5 Reviews on Feb 17, 2015 (Avg. rating: 4.8)
• 5 Reviews on Feb 21, 2015 (Avg. rating: 4.8)
• 5 Reviews on May 18, 2015 (Avg. rating: 4.8)
• 5 Reviews on Mar 4, 2016 (Avg. rating: 4.8)
• 5 Reviews on Mar 13, 2015 (Avg. rating: 4.6)
• 5 Reviews on Feb 22, 2015 (Avg. rating: 3.8)
Show All

In total, we found that 132 reviews were created on just 21 days. The reviews on these high volume days have rated this product an average of 4.7 while reviews from other days have rated this product an average of 4.5. 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.

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 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.

• 
• 30%
• Used substantial repetitive phrases

317 of the 1,041 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 4.4. 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 Phrase Repetition test.

• 13
• Reviews have been deleted

We discovered a total of 13 deleted Reviews for this product, with an average rating of 4.5. 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

• 
• 42%
• 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:

• 26-40 words: 41.8% (Avg. rating: 4.6)

In total, we found that 435 reviews (or 42%) are within an overrepresented word count group. While this is more reviews from overrepresented word count groups than we'd expect to see, the discrepancy in ratings between reviews with overrepresented word groups and all other reviews isn’t significant enough to rule out the possibility of it being due to random chance.

Read more about our Word Count Comparison test.

• 
• 48%
• 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 6-15 Reviews: 47.9% (Avg. rating: 4.6)

In total, we found that 499 reviewers (or 48%) 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.

• 
• 40%
• Unverified Purchases

420 of the 1,041 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

• 
• 6%
• have only posted one review

63 of the 1,041 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

• 
• 13%
• have zero verified purchases

135 of the 1,041 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

• 
• 8%
• have previously deleted reviews

81 of the 1,041 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

3 of the 1,041 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.

• 
• 17%
• Substantial overlapping review history

175 of the 1,041 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

• 
• 2%
• Reviewed other products from this brand

21 of the 1,041 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

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.