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

• 
• 1%
• Admitted to receiving an incentive

1 of the 138 total reviews for this product admitted to receiving a free or discounted product in exchange for a review. Incentivized reviews have rated this product an average of 3.0 while reviews that were not incentivized rated this product an average of 4.8. 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 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 4.7, while the average ease score for reviewers in this category is 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.

• 1
• Review has been deleted

We discovered a total of 1 deleted Review for this product, with an average rating of 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

• 
• 27%
• Created over 7 days

We counted 138 reviews for this product over the span of 786 days, an average of 0.2 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 7 days exceeding this threshold:

• 8 Reviews on Jul 21, 2014 (Avg. rating: 5.0)
• 7 Reviews on Jul 15, 2014 (Avg. rating: 4.7)
• 5 Reviews on Jul 25, 2014 (Avg. rating: 5.0)
• 5 Reviews on Jul 31, 2014 (Avg. rating: 5.0)
• 4 Reviews on Jul 30, 2014 (Avg. rating: 5.0)
• 4 Reviews on Jan 28, 2015 (Avg. rating: 5.0)
• 4 Reviews on Feb 14, 2016 (Avg. rating: 5.0)
Show All

In total, we found that 37 reviews were created on just 7 days. This is an excessively high number of reviews submitted on these high volume days.

Read more about our Rating Trend test.

• 
• 67%
• Unverified Purchases

93 of the 138 total reviews for this product are unverified purchases. While this is a higher percentage of unverified purchases than we'd expect to see, it does not appear to have a significant impact on the overall rating.

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.

Never-Verified Reviewers

• 
• 24%
• have zero verified purchases

33 of the 138 reviewers have never written a verified purchase review. While this is more Never-Verified Reviewers than we'd expect to see, the discrepancy in ratings between the Never-Verified Reviewers and reviewers who have written at least one verified purchase review isn't significant enough to rule out the possibility of it being due to random chance.

Take-Back Reviewers

• 
• 9%
• have previously deleted reviews

12 of the 138 reviewers have had at least one of their past reviews for another product deleted. While this is more Take-Back 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.

• 
• 47%
• 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:

• 101-200 words: 47.1% (Avg. rating: 4.9)

In total, we found that 65 reviews (or 47%) 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.

• 
• 68%
• Used substantial repetitive phrases

94 of the 138 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.

• 
• 30%
• Substantial overlapping review history

41 of the 138 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.

• 
• 0%
• From reviewers with an overrepresented participation

We didn't find any participation groups that had a statistically significant greater concentration than what we'd expect to see in this category.
Read more about our Reviewer Participation test.

Brand Repeaters

• 
• 8%
• Reviewed other products from this brand

11 of the 138 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.