• 29
• Reviews have been deleted

We discovered a total of 29 deleted Reviews for this product, with an average rating of 4.7. 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

• 
• 29%
• Created over 17 days

We counted 466 reviews for this product over the span of 1,065 days, an average of 0.4 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 17 days exceeding this threshold:

• 13 Reviews on Sep 16, 2016 (Avg. rating: 4.9)
• 11 Reviews on Aug 11, 2016 (Avg. rating: 5.0)
• 11 Reviews on Nov 18, 2015 (Avg. rating: 4.8)
• 11 Reviews on Feb 29, 2016 (Avg. rating: 4.8)
• 11 Reviews on Sep 13, 2016 (Avg. rating: 4.8)
• 11 Reviews on Sep 14, 2016 (Avg. rating: 4.8)
• 10 Reviews on Mar 2, 2016 (Avg. rating: 4.9)
• 9 Reviews on Sep 18, 2016 (Avg. rating: 4.8)
• 8 Reviews on Sep 15, 2016 (Avg. rating: 5.0)
• 7 Reviews on Sep 20, 2016 (Avg. rating: 4.9)
• 5 Reviews on Nov 20, 2015 (Avg. rating: 5.0)
• 5 Reviews on Sep 19, 2016 (Avg. rating: 5.0)
• 5 Reviews on Sep 26, 2016 (Avg. rating: 5.0)
• 5 Reviews on Sep 28, 2016 (Avg. rating: 5.0)
• 5 Reviews on Oct 13, 2016 (Avg. rating: 5.0)
• 5 Reviews on Nov 21, 2014 (Avg. rating: 4.8)
• 5 Reviews on Sep 17, 2016 (Avg. rating: 4.8)
Show All

In total, we found that 137 reviews were created on just 17 days. The reviews on these high volume days have rated this product an average of 4.9 while reviews from other days have 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 Rating Trend test.

Take-Back Reviewers

• 
• 16%
• have previously deleted reviews

73 of the 466 reviewers have had at least one of their past reviews for another product deleted. This is an excessively large percentage of Take-Back Reviewers which may indicate unnatural reviews.

Read more about our Suspicious Reviewers 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 4.5, 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.

• 
• 14%
• Used substantial repetitive phrases

65 of the 466 total reviews for this product use substantial repetitive phrases between them. These reviewers have rated this product an average of 5.0 while reviews without substantial repetitive phrases 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 Phrase Repetition test.

• 
• 30%
• 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:

• 6-15 words: 30.3% (Avg. rating: 4.8)

In total, we found that 141 reviews (or 30%) are within an overrepresented word count group. While this is more reviews from overrepresented word count 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 Word Count Comparison test.

• 
• 59%
• 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: 26.8% (Avg. rating: 4.8)
• Reviewers with 6-15 Reviews: 32.0% (Avg. rating: 4.9)

In total, we found that 274 reviewers (or 59%) 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.

• 
• 31%
• Unverified Purchases

145 of the 466 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.

• 
• 13%
• Substantial overlapping review history

59 of the 466 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

1 of the 466 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.