Close
A Dictionary of Basic Japanese Grammar
More product info
From Seiichi Makino
This report was last updated 7/15/2019.
Refresh the report to view the most up-to-date data available:
Refresh the report to view the most up-to-date data available:
View/Edit Adjustment
Jump to Report Card
Report Info:
Note: While Amazon.com claims 105 Ratings, we counted 20 Reviews available on their site.
Note: We only analyze "reviews" and ignore one-tap "ratings".
Note: We only analyze "reviews" and ignore one-tap "ratings".
Top products in Foreign Language Study & Reference with authentic reviews:
Report Card
Pass Overall Grade
FAIL Deleted Reviews
FAIL Suspicious Reviewers
WARN Reviewer Ease
PASS Rating Trend
PASS Unverified Purchases
PASS Word Count Comparison
PASS Phrase Repetition
PASS Overlapping Review History
PASS Reviewer Participation
PASS Brand Repeats
PASS Incentivized Reviews
Most Trusted Reviews
I bought this book to refresh my memory in Japanese ... [Go to full review]
Feb 4, 2018
100%
TRUST
TRUST
- Verified Purchaser
- Take-Back Reviewer (1 deleted Review; avg. rating: 5.0)
- Easy Grader (avg. rating: 4.6)
Least Trusted Reviews
Good for searching grammar points. I use this at work [Go to full review]
Jan 24, 2018
35%
TRUST
TRUST
- Verified Purchaser
- Single-Day Reviewer (posted all reviews on Jan 24, 2018)
- Take-Back Reviewer (1 deleted Review; avg. rating: 5.0)
- Brand Repeater (2 of 8 reviews for this brand; avg rating: 5.0)
- Easy Grader (avg. rating: 4.9)
Analysis Details
Fail Deleted Reviews
We discovered a total of 87 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:
- 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.
Fail Suspicious Reviewers
Take-Back Reviewers
4 of the 20 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.
Single-Day Reviewers
3 of the 20 reviewers have written multiple reviews but posted all of them on a single day. While this is more Single-Day Reviewers than we'd expect to see, the discrepancy in ratings between the Single-Day Reviewers and all other reviewers isn't significant enough to rule out the possibility of it being due to random chance.
Warn 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 4.6, while the average ease score for reviewers in this category is 4.4. While this discrepancy is rather large, it is not quite large enough to rule out the possibility of it being due random chance.
4.6 Product's Average Ease Score
4.4 Category's Average Ease Score
Read more about our Reviewer Ease test.
Pass Rating Trend
-
- 0%
- Created over 2 days
We counted 20 reviews for this product over the span of 588 days, an average of 0.0 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 1 or fewer reviews on any given day.
However, we see the following 2 days exceeding this threshold:In total, we found that 0 reviews were created on just 2 days. 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 Rating Trend test.
However, we see the following 2 days exceeding this threshold:In total, we found that 0 reviews were created on just 2 days. 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 Rating Trend test.
Pass Unverified Purchases
-
- 0%
- Unverified Purchases
0 of the 20 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.
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 Word Count Comparison
-
- 0%
- Have an overrepresented word count
We didn't find any review word count groups that had a statistically significant greater concentration than what we'd expect to see in this category.
Read more about our Word Count Comparison test.
Read more about our Word Count Comparison test.
Pass Phrase Repetition
-
- 0%
- Used substantial repetitive phrases
0 of the 20 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.
Read more about our Phrase Repetition test.
Read more about our Phrase Repetition test.
Pass Overlapping Review History
-
- 0%
- Substantial overlapping review history
0 of the 20 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.
Read more about our Overlapping Review History test.
Pass Reviewer Participation
-
- 0%
- From reviewers with an overrepresented participation
We didn't find any participation groups that had a statistically significant greater concentration than what we'd expect to see in this category.
Read more about our Reviewer Participation test.
Read more about our Reviewer Participation test.
Pass Brand Repeats
Brand Repeaters
We didn't detect a substantial amount of Brand Repeaters.
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.
-
- 0%
- Admitted to receiving an incentive
We didn't detect any reviews that used language indicating they were incentivized.
Read more about our Incentivized Reviews test. Check out our study showing that Incentivized Reviewers are much more likely to leave a positive review.
Read more about our Incentivized Reviews test. Check out our study showing that Incentivized Reviewers are much more likely to leave a positive review.