• 24
• Reviews have been deleted

We discovered a total of 24 deleted Reviews for this product, with an average rating of 4.8. 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

• 
• 55%
• Created over 8 days

We counted 117 reviews for this product over the span of 175 days, an average of 0.7 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 5 or fewer reviews on any given day.

However, we see the following 8 days exceeding this threshold:

• 10 Reviews on Jul 27, 2016 (Avg. rating: 4.9)
• 10 Reviews on Aug 2, 2016 (Avg. rating: 4.7)
• 9 Reviews on Jul 29, 2016 (Avg. rating: 4.4)
• 8 Reviews on Aug 1, 2016 (Avg. rating: 5.0)
• 8 Reviews on Jul 30, 2016 (Avg. rating: 4.9)
• 7 Reviews on Jul 25, 2016 (Avg. rating: 5.0)
• 6 Reviews on Jul 31, 2016 (Avg. rating: 5.0)
• 6 Reviews on Jul 24, 2016 (Avg. rating: 4.8)
Show All

In total, we found that 64 reviews were created on just 8 days. The reviews on these high volume days have rated this product an average of 4.8 while reviews from other days 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 Rating Trend test.

• 
• 83%
• Unverified Purchases

97 of the 117 total reviews for this product are unverified purchases. The unverified purchasers have rated this product an average of 4.8 while the verified purchasers have rated this product an average of 3.8. 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.

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.

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

• 
• 58%
• Admitted to receiving an incentive

68 of the 117 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 4.8 while reviews that were not incentivized 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 Incentivized Reviews test. Check out our study showing that Incentivized Reviewers are much more likely to leave a positive review.

Take-Back Reviewers

• 
• 53%
• have previously deleted reviews

62 of the 117 reviewers have had at least one of their past reviews for another product deleted. The Take-Back Reviewers have rated this product an average of 4.8 while the reviewers who don't have any deleted reviews in their history 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.

Single-Day Reviewers

• 
• 2%
• have posted all their reviews on a single day

2 of the 117 reviewers have written multiple reviews but posted all of them on a single day. The Single-Day reviewers have rated this product an average of 2.5 while all other reviewers rated this product an average of 4.7. 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 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 4.7, 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.

• 
• 65%
• Used substantial repetitive phrases

76 of the 117 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 4.3. 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.

• 
• 82%
• Substantial overlapping review history

96 of the 117 reviewers have substantial overlapping product review history. These reviewers have rated this product an average of 4.8 while the reviewers who have a more unique product review history rated this product an average of 3.8. 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 Overlapping Review History test.

• 
• 22%
• 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: 22.2% (Avg. rating: 4.6)

In total, we found that 26 reviews (or 22%) are within an overrepresented word count group. 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 Word Count Comparison test.

• 
• 18%
• 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 101-200 Reviews: 18.0% (Avg. rating: 4.8)

In total, we found that 21 reviewers (or 18%) are within an overrepresented participation group. 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 Reviewer Participation test.

Brand Repeaters

We didn't detect a substantial amount of Brand Repeaters.