To begin with, your Trust Network is preset with a list of other users whose Feedback ratings you trust automatically.
Those users were chosen in a special procedure that's detailed
down below.
When those users leave negative Feedback for a user, his Trust Score turns red.
If they leave positive Feedback, his Trust Score turns green.
This Trust Score is not displayed all over the forum, but only in boards where goods or services are offered.
These presets are probably useful for you as a newbie at bitcointalk, as long as you don't know the people around here.
Unfortunately, it happens that even users with green scores turn out to be scammers.
Green Trust doesn't mean you should be careless!Red Trust, on the other hand, usually means you should take care.
Once you start making your own experiences with other users by trading, or when you feel that you are finally able to judge people's trustworthiness, you should start leaving your own Feedback.
This Feedback will alter the Trust Score of users only in your own eyes at first.
Others won't see the Feedback you leave at first*, and the Trust Score they see won't be affected by your Feedback.
For now, the Feedback you leave will only be meaningful for yourself.
* they may chose to view this "private" Feedback if they so wish, though.
Advanced use of the Trust SystemThe day might come when you no longer want to rely on the judgment of a preset group of users, but rather chose yourself whose Feedback to trust.
To do so, it's necessary to work on your own Trust List.
The Trust List settings can be found here:
https://bitcointalk.org/index.php?action=trustYou may wonder why there's no list of users there, as I've explained above, but rather a single entry called "DefaultTrust".
DefaultTrust is a special user who maintains his own Trust List.
The Trust List of DefaultTrust includes the names of those preset users I've talked about.
Beneath the list, there's a value called "Depth". This value represents the number of "steps down" which the forum's software will look into Trust Lists of people in your own Trust List, to construct your final, complete list.
Let's view a simple example. Depth is 1.
DefaultTrust's Trust List
* Alice
* Bob
Alice's Trust List
* Carol
* Dan
* Eve
Bob's Trust List
* Frank
* Grace
* ~Eve
As you can see, "Eve" is in two lists, in one of them with a prefix "~".
The final Trust List that the forum's software will generate will now look like this:
* DefaultTrust
* Alice
* Bob
* Carol
* Dan
* Frank
* Grace
Those are the people whose judgment you trust for the moment.
All Feedback left by those users will be taken into account to calculate the Trust Score you'll see displayed.
Of course, your own Feedback will be taken into account as well.
You might have noticed that Eve doesn't show up in the final list.
The reason is simply that Eve is added "positively" to the Trust List of Alice, but at the same time, by the prefix "~", Bob tells us that he explicitly distrusts the judgment of Eve.
The software will now calculate "+ Eve" and "- Eve", which equals "Zero Eve", so Eve won't show up.
Actually, that's not true, a score of 0 will still keep Eve on the list, only a negative score, i.e. more people distrusting Eve than trusting her will lead to her exclusion.
I'll leave the example with only two lists standing for simplicity's sake, though.
Now, to set up your own Trust List, you might not want to create one from scratch.
To create a list based on other users' judgements, you may just include other users' Feedback by including their names into your own Trust List and set Depth to 1.
If you believe that the people in your Trust List not only leave valuable Feedback, but also maintain good Trust Lists themselves, feel free to set Depth to 2.
I advise against higher values for Depth. That will lead to a final Trust List that includes an enormous number of people.
If you're convinced of a specific user's "bad judgment", you may simply include their name with the prefix "~".
Away with his Feedback and his Trust List, no matter how many people have included him or her.
In the extreme case where you don't want to trust anyone's judgment but your own, you may just want to include the single entry "~DefaultTrust", with a Depth of 0, preferably.
Depth 0 means that you will only take into account the Feedback of the users in your Trust List, but not their Trust Lists.
DefaultTrust doesn't leave Feedback of his own, by the way, so you might as well keep DefaultTrust without the "~" at Depth 0.
Unfortunately, there's no way to set a specific Depth for each user in your Trust List, e.g. when you know someone whose Feedback you consider valuable but whose Trust List is a mess.
Now that'd be an improvement suggestion for the Trust System, right?I hope this short introduction helps you understand the Trust System a little better.
Once you've come to understand it, you'll notice that it's an elegant system with its two distinct lists, Feedback and Trust List. The combination of which allows for quite some finetuning.
Unfortunately, most users misunderstand how the trust system works.
TL;DR:Feedback is where your direct experience with other users goes (trading etc.) and / or your "opinion" about the trustworthiness of a certain user.
Trust List is where users go whose Feedback you consider valuable.
A lot of people confuse the two and put people in their Trust List whom they trust.
This is in most cases useless, and in a few cases even harmful.