What is a "critical success" in crafting?

Reading through the page on the Guild Wars 2 wiki regarding crafting experience it makes mention to a 'Critical Success':

A critical success in crafting can either grant an experience bonus or refund some of the materials used but does not add to the value or stats of the item crafted.

What exactly is a 'Critical Success', and how do you know when you have succeeded in such a way? I am presuming this is similar to Critical Chance but for crafting, although the article doesn't specify that...

Solution 1:

There is a small chance of getting critical success when crafting an item. When that happens you will get 15-50% bonus CXP or have some of the materials you used "refunded".

You can also increase the chance for critical success for 3/6/9% per tier by gaining artisan bonus via Power of the Mists mechanic in World vs World.

When you get the critical chance you will see x exp + y exp on your screen, the x = normal cxp you get from crafting and the y = bonus cxp which you get from critical chance and/or recipe discovery.

From what i noticed by watching videos of people crafting on youtube, when you get item refund via critical chance there is no message about it.

Sources: 1 , 2 , 3

Solution 2:

Yes, there is a critical chance modifier for crafting. If you pull up the WvW scoreboard in-game (default key = B), you can see that one of the bonuses your server can receive from WvW is an increased chance to have a critical success while crafting (Artisan bonus).

When you receive the experience bonus for crafting, you should see something like "12345 xp + 1234 xp" flash up on the screen. The "+ 1234 xp" portion is the bonus experience that you wouldn't see on a non-critical success. I don't know that there is a message that flashes up when materials are refunded, so I would guess you would have to know how much of each material you started out with and compare that to what you have at the end. Hope this helps.