• 440
• Reviews have been deleted

We discovered a total of 440 deleted Reviews for this product, with an average rating of 4. 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

• 
• 38%
• Created over 40 days

We counted 1,602 reviews for this product over the span of 6,298 days, an average of 0.3 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 40 days exceeding this threshold:

• 140 Reviews on Mar 25, 2003 (Avg. rating: 4.4)
• 125 Reviews on Mar 26, 2003 (Avg. rating: 4.4)
• 58 Reviews on Mar 27, 2003 (Avg. rating: 4.4)
• 28 Reviews on Mar 28, 2003 (Avg. rating: 4.4)
• 22 Reviews on Mar 29, 2003 (Avg. rating: 4.2)
• 15 Reviews on Apr 4, 2003 (Avg. rating: 4.2)
• 13 Reviews on Apr 2, 2003 (Avg. rating: 3.7)
• 12 Reviews on Apr 5, 2003 (Avg. rating: 4.5)
• 12 Reviews on Mar 31, 2003 (Avg. rating: 4.3)
• 11 Reviews on Mar 30, 2003 (Avg. rating: 4.4)
• 11 Reviews on Apr 3, 2003 (Avg. rating: 4.0)
• 10 Reviews on Apr 16, 2003 (Avg. rating: 4.2)
• 10 Reviews on Apr 1, 2003 (Avg. rating: 3.6)
• 9 Reviews on Apr 20, 2003 (Avg. rating: 4.2)
• 9 Reviews on Apr 9, 2003 (Avg. rating: 4.1)
• 8 Reviews on Jun 4, 2003 (Avg. rating: 4.3)
• 7 Reviews on Apr 7, 2003 (Avg. rating: 4.3)
• 6 Reviews on Apr 11, 2003 (Avg. rating: 4.3)
• 6 Reviews on Apr 15, 2003 (Avg. rating: 4.3)
• 5 Reviews on Apr 8, 2003 (Avg. rating: 4.6)
• 5 Reviews on Apr 10, 2003 (Avg. rating: 4.6)
• 5 Reviews on May 3, 2003 (Avg. rating: 4.6)
• 5 Reviews on Apr 13, 2003 (Avg. rating: 4.4)
• 5 Reviews on Apr 27, 2003 (Avg. rating: 4.4)
• 5 Reviews on Jan 21, 2004 (Avg. rating: 4.2)
• 5 Reviews on May 8, 2003 (Avg. rating: 4.2)
• 5 Reviews on Apr 6, 2003 (Avg. rating: 4.2)
• 5 Reviews on Apr 14, 2003 (Avg. rating: 3.4)
• 4 Reviews on Jun 12, 2003 (Avg. rating: 5.0)
• 4 Reviews on Oct 11, 2003 (Avg. rating: 5.0)
• 4 Reviews on Dec 18, 2003 (Avg. rating: 5.0)
• 4 Reviews on Apr 12, 2003 (Avg. rating: 4.5)
• 4 Reviews on Sep 24, 2003 (Avg. rating: 4.5)
• 4 Reviews on Apr 19, 2003 (Avg. rating: 4.3)
• 4 Reviews on May 5, 2003 (Avg. rating: 4.0)
• 4 Reviews on Jan 19, 2004 (Avg. rating: 4.0)
• 4 Reviews on Apr 23, 2003 (Avg. rating: 3.5)
• 4 Reviews on May 17, 2003 (Avg. rating: 3.5)
• 4 Reviews on Nov 8, 2003 (Avg. rating: 3.5)
• 4 Reviews on Sep 27, 2003 (Avg. rating: 3.0)
Show All

In total, we found that 605 reviews were created on just 40 days. The reviews on these high volume days have rated this product an average of 4.3 while reviews from other days 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 Rating Trend test.

One-Hit Wonders

• 
• 24%
• have only posted one review

390 of the 1,602 reviewers have only reviewed this product. The One-Hit Wonders have rated this product an average of 4.4 while the reviewers who have posted more than one review 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.

Never-Verified Reviewers

• 
• 67%
• have zero verified purchases

1,075 of the 1,602 reviewers have never written a verified purchase review. This is an excessively large percentage of Never-Verified Reviewers which may indicate unnatural reviews.

Single-Day Reviewers

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

26 of the 1,602 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 4.7 while all other reviewers 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 Suspicious Reviewers test.

• 
• 34%
• Used substantial repetitive phrases

542 of the 1,602 total reviews for this product use substantial repetitive phrases between them. These reviewers have rated this product an average of 4.4 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.

• 
• 84%
• Unverified Purchases

1,343 of the 1,602 total reviews for this product are unverified purchases. This is an excessively large percentage of unverified purchases and it may indicate 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.

Brand Repeaters

• 
• 27%
• Reviewed other products from this brand

432 of the 1,602 reviewers have reviewed other products for this brand. While this is more Brand Repeaters than we'd expect to see, it does not appear to have a significant impact on the overall rating.

Brand Loyalists

• 
• 3%
• Reviewed mostly products from this brand

43 of the 1,602 reviewers have reviewed multiple products but half or more of their reviews are for this brand. While this is more Brand Loyalists than we'd expect to see, the discrepancy in ratings between the Brand Loyalists and non-loyalists isn't significant enough to rule out the possibility of it being due to random chance.

Read more about our Brand Repeats test.

• 
• 72%
• 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: 47.3% (Avg. rating: 4.3)
• Reviewers with 6-15 Reviews: 24.8% (Avg. rating: 3.9)

In total, we found that 1155 reviewers (or 75%) 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.

• 
• 24%
• 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: 24.0% (Avg. rating: 4.0)

In total, we found that 385 reviews (or 24%) 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.

• 
• 28%
• Substantial overlapping review history

441 of the 1,602 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.

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 4.2, while the average ease score for reviewers in this category is 4.3.

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 1,602 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.