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Takamachi Ryoko



Joined: 27 Apr 2008
Posts: 155
Location: 東京, 日本

PostPosted: Thu Jan 31, 2013 1:04 am Reply with quote
A few days ago, I noticed that the stats of some show have been altered. For example, Btooom!: anime#14418. The "Masterpiece" that time was around 140s, then on Monday it went to 170s, yesterday was 180s and Wednesday it's 198; if this keeps up today it's going to pass 200. In other word, one day its "Masterpiece" just increase 10 votes. Is it possible for it to have so many "Masterpiece" votes in just a three days? Even the "Excellent" part didn't exceed 80.

Looks like someone just voted "Masterpiece" many times on many accounts to raise its stat. While I'm not a fan of the series but can it be fixed? It's really one-sided this way.
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Dessa
Baka RangerBaka Ranger


Joined: 14 Jul 2004
Posts: 2493

PostPosted: Thu Jan 31, 2013 3:28 am Reply with quote
Dan explained the way the ratings work a bit here.

TL;DR - the spammers aren't gonna make a difference in the weighted average rating for the title anyway.
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Takamachi Ryoko



Joined: 27 Apr 2008
Posts: 155
Location: 東京, 日本

PostPosted: Thu Jan 31, 2013 7:49 am Reply with quote
Yeah, even if the rating changed, it wouldn't affect one's opinion. But just let the spammer running amok is kinda disturbing though. Can anyone fix it?
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dtm42



Joined: 05 Feb 2008
Posts: 12767
Location: NZL

PostPosted: Thu Jan 31, 2013 8:07 am Reply with quote
It's a problem that will probably always plague the Encyclopedia as long as users can submit ratings, but I don't know if it needs fixing. The spammers can't really affect the Weighted Average, not by an appreciable amount anyway. In a way, they're just wasting their time. All you need to remember is to check the Weighted Average rather than the normal Bayesian rating.
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Dan42
Chief Encyclopedist


Joined: 02 Jan 2002
Posts: 3250
Location: Montreal

PostPosted: Wed Feb 13, 2013 7:32 am Reply with quote
The Bayesian rating is based on the Weighted average, and is definitely the one you should pay attention to. If you want to know how much effect the spammers would have otherwise, look at the difference between the Weighted average and the Arithmetic mean.
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dtm42



Joined: 05 Feb 2008
Posts: 12767
Location: NZL

PostPosted: Wed Feb 13, 2013 2:48 pm Reply with quote
I stand corrected. I never knew that the Bayesian was based on the Weighted Average - I had mistakenly thought it was the other way around.
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guildmaster



Joined: 17 Dec 2012
Posts: 325
Location: Hot & Humid FL

PostPosted: Thu Feb 28, 2013 1:45 am Reply with quote
Dessa wrote:
Dan explained the way the ratings work a bit here.

TL;DR - the spammers aren't gonna make a difference in the weighted average rating for the title anyway.


The linked answer begs the question; what is a trustworthy user vs. an untrustworthy user?
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dtm42



Joined: 05 Feb 2008
Posts: 12767
Location: NZL

PostPosted: Thu Feb 28, 2013 2:25 am Reply with quote
A 'trustworthy user' is someone who honestly rates titles, such that there is a decent spread of good and bad titles in their list of Anime. 'Untrustworthy users' only rate very highly or very lowly, usually to skew the ratings of a title in the desired direction (up or down). The Weighted Average gives less 'weight' to the opinions of such users, and more 'weight' to those users who rate titles honestly.
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guildmaster



Joined: 17 Dec 2012
Posts: 325
Location: Hot & Humid FL

PostPosted: Thu Feb 28, 2013 6:49 am Reply with quote
dtm42 wrote:
A 'trustworthy user' is someone who honestly rates titles, such that there is a decent spread of good and bad titles in their list of Anime. 'Untrustworthy users' only rate very highly or very lowly, usually to skew the ratings of a title in the desired direction (up or down). The Weighted Average gives less 'weight' to the opinions of such users, and more 'weight' to those users who rate titles honestly.


Interesting.

Over 2/3 of my "my anime" listings are series that I have purchased. I try to only buy something if i think I'm going to like it, so i would expect that most of my ratings would be on the upper half of the scale. Not to say that I haven't bought some duds, which i have noted.

I also have to go through the lists again for more "seen some" entries, although I'm trying to not put DBZ, PM DM, YuGiOh, CardCaptors, Sailor Moon, etc. on my seen some charts, because I can't stand them, and if i do, I'll rate them honestly (from my point of view), but it won't be high. I have seen them as a consequence of the rugrats in the family when they were younger gluing themselves to the TV.

But I still haven't watched over half of what I bought so i have a ways to go just getting through them.
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dtm42



Joined: 05 Feb 2008
Posts: 12767
Location: NZL

PostPosted: Thu Feb 28, 2013 7:06 am Reply with quote
You're right, people generally only watch things they'll like. Lots of people have lists that only go from - say - Masterpiece to Not Really Good. Those people are still considered trustworthy users.

Basically, the system has been set up that as long as you rate honestly then you will be a trustworthy user. Don't worry about trying to make your list conform to a bell curve, just be honest.
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guildmaster



Joined: 17 Dec 2012
Posts: 325
Location: Hot & Humid FL

PostPosted: Thu Feb 28, 2013 7:21 am Reply with quote
Cool, Thanks.

NZL - New Zealand? with 90% of the US still sleeping or just waking up, I figured you're not there.

Some fascinating scenery there. LOTR was filmed there - correct?
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dtm42



Joined: 05 Feb 2008
Posts: 12767
Location: NZL

PostPosted: Thu Feb 28, 2013 8:28 am Reply with quote
Glad I could help.

It's 2:30am in New Zealand right now; I keep crazy hours.

And yes, LoTR was filmed here.
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