Mental Math: Tricks To Become A Human Calculator (For Speed Math, Math Tricks, Vedic Math...
More product info
From Abhishek V R
Refresh the report to view the most up-to-date data available:
Refresh Report
Report Card
Most Trusted Reviews
TRUST
- Verified Purchaser
- Take-Back Reviewer (3 deleted Reviews; avg. rating: 4.3)
- Overlapping Review History: reviewed 1 of 9 top products
- Critical Reviewer (avg. rating: 3.9)
Least Trusted Reviews
TRUST
- Verified Purchaser
- Contains repetitive phrases (show)
- Overrepresented Participation (posted 2 Reviews)
- Easy Grader (avg. rating: 5.0)
Analysis Details
We discovered a total of 7 deleted Reviews for this product, with an average rating of 5. 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.
4.8 Product's Average Ease Score
4.3 Category's Average Ease Score
Read more about our Reviewer Ease test.
-
- 76%
- 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:In total, we found that 61 reviewers (or 76%) are within an overrepresented participation group. These reviews have rated this product an average of 5.0, while all other reviews have rated this product an average of 4.6. 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.
-
- 8%
- Created over 1 day
We counted 80 reviews for this product over the span of 105 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 1 day exceeding this threshold:In total, we found that 6 reviews were created on just 1 day. Although any days with a larger number of reviews than expected is suspicious, these reviews do not appear to have a significant impact on the overall rating.
One-Hit Wonders
8 of the 80 reviewers have only reviewed this product. While this is more One-Hit Wonders than we'd expect to see, the discrepancy in ratings between the One-Hit Wonders and reviewers who have posted more than one review isn't significant enough to rule out the possibility of it being due to random chance.
Take-Back Reviewers
2 of the 80 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.
-
- 56%
- 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 2 groups with a statistically significant greater concentration than what we'd expect to see:In total, we found that 45 reviews (or 56%) are within an overrepresented word count group. This is an excessively high number of reviews in overrepresented word count groups.
21 of the 80 total reviews for this product use substantial repetitive phrases between them. This is an excessively large percentage which may indicate unnatural reviews.
12 of the 80 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.
10% also reviewed:
Insane Productivity for Lazy People: A Complete... by Andrii Sedniev
9% also reviewed:
2700+ Animal Jokes and Riddles for Kids: Animal... by Kid's Corner Publishing
9% also reviewed:
Instant Pot Cookbook: 5 Ingredients or Less –... by Tyler Smith
9% also reviewed:
Guitar: Learn to Play the Guitar: A Step-by-Step... by Trevor Beck
8% also reviewed:
Cryptocurrency: Everything you need to know about... by Matthew Connor
8% also reviewed:
Instant Pot Cookbook: 777 Instant Pot Recipes.... by Roy Fisher
8% also reviewed:
Penny Stocks: A Beginner's Guide to Earning ... by T Whitmore
8% also reviewed:
Sleep Your Way to Good Health: 7 Steps to Make... by Amy Jenkins
from the same brand
32 of the 80 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.
Brand Repeaters
-
- 0%
- 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.