Stumbling on Happiness
More product info
From Daniel Gilbert
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Report Card
Most Trusted Reviews
TRUST
- Verified Purchaser
- Critical Reviewer (avg. rating: 4.2)
Least Trusted Reviews
TRUST
- Unverified Purchaser
- Overrepresented word count (120 words)
- Contains repetitive phrases (show)
- Never-Verified Reviewer
- Easy Grader (avg. rating: 5.0)
Analysis Details
We discovered a total of 15 deleted Reviews for this product, with an average rating of 4.3. 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.
Never-Verified Reviewers
Less than approximately 10% of reviewers have never written a verified purchase review. The Never-Verified Reviewers have rated this product an average of 4.5 while the reviewers who have written at least one verified purchase review rated this product an average of 3.7. 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.
Take-Back Reviewers
Approximately 30% of 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, the discrepancy in ratings between the Take-Back Reviewers and reviewers who don't have any deleted reviews in their history isn't significant enough to rule out the possibility of it being due to random chance.
Approximately 20% of reviews 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 3.6. 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.
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- ~45%
- 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:In total, we found that approximately 45% 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.
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- <10%
- Created on high-volume days
Read more about our Rating Trend test.
269 of the 1,615 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.
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Approximately 20% of 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.
4.1 Product's Average Ease Score
4.3 Category's Average Ease Score
Read more about our Reviewer Ease test.
Brand Repeaters
Less than approximately 10% of 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.
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- <10%
- Admitted to receiving an incentive
Read more about our Incentivized Reviews test. Check out our study showing that Incentivized Reviewers are much more likely to leave a positive review.