The Sign of the Four (Sherlock Holmes Book 2)
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From Sir Arthur Conan Doyle
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Top products in Books with authentic reviews:
Warn Overall Grade
FAIL Suspicious Reviewers
FAIL Word Count Comparison
WARN Deleted Reviews
WARN Rating Trend
WARN Reviewer Participation
PASS Unverified Purchases
PASS Phrase Repetition
PASS Overlapping Review History
PASS Reviewer Ease
PASS Brand Repeats
PASS Incentivized Reviews
Most Trusted Reviews
good book [Go to full review]
Oct 1, 2018
- Verified Purchaser
- Take-Back Reviewer (2 deleted reviews; avg. rating: 3.0)
- Easy Grader (avg. rating: 4.4)
Least Trusted Reviews
It was written by Sir Arthur Conan Doyle. He is ... [Go to full review]
Dec 28, 2012
- Verified Purchaser
- Created on a high volume day
- Overrepresented word count (33 words)
- Take-Back Reviewer (1 deleted review; avg. rating: 5.0)
- Overrepresented Participation (posted 9 reviews)
- Critical Reviewer (avg. rating: 3.8)
Fail Suspicious Reviewers
1,870 of the 6,000 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.
Fail Word Count Comparison
- 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 3 groups with a statistically significant greater concentration than what we'd expect to see:
Warn Deleted Reviews
We discovered a total of 206 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:
- 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.
- We have no information on reviews that were never published in the first place.
- 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.
4.7 average rating of deleted reviews
Show distribution of deleted reviews
Warn Rating Trend
- Created over 140 days
We counted 6,000 reviews for this product over the span of 7,958 days, an average of 0.8 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 140 days exceeding this threshold:
Warn Reviewer Participation
- From reviewers with an overrepresented participation
We see the following 3 participation groups with a statistically significant greater concentration than what we'd expect to see:
Pass Unverified Purchases
966 of the 6,000 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.
Pass Phrase Repetition
Reviews that contain one of these phrases are NOT necessarily devalued; read more about how this test works here.
Common Phrases in Reviews:
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537 of the 6,000 total reviews for this product use substantial repetitive phrases between them. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.
Pass Overlapping Review History
Reviewers of this product have ALSO reviewed the following products:
Does not include products
from the same brand
from the same brand
887 of the 6,000 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.
Pass Reviewer Ease
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 4.3, while the average ease score for reviewers in this category is 4.3.
4.3 Product's Average Ease Score
4.3 Category's Average Ease Score
Read more about our Reviewer Ease test.
Pass Brand Repeats
659 of the 6,000 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.
Pass Incentivized Reviews
On Oct 3, 2016, Amazon prohibited incentivized reviews, however we still test for them since there are still millions in our dataset.
2 of the 6,000 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, or check out our study showing that Incentivized Reviewers are much more likely to leave a positive review.