What does "Increases Critical Heal Bonus" mean?

Take these two items from ArcheAge:

They both appear to increase "critical heal bonus" by a percentage. I've asked some other experienced players in game, and I got some conflicting responses. Keeping in mind that this is a Korean game that has been translated into English, what does this mean exactly? Is this increasing the critical chance of a healing ability, or is it increasing the amount healed when a healing ability does crit?

tl;dr The "Increase Critical Heal Bonus" should be an increase in the amount you heal on a critical heal.

From what I have been able to find (mostly in this guide), it seems as though those specific items giving you "Increased Critical Heal Bonus" are increasing the amount of heal you do on a critical heal.

What seems to increase the critical heal rate (the chance of getting a critical heal) is your Spirit level.

Spirit: Is converted to Healing Power. 1 Spirit = 0.2 Healing Power. Also increases your Healing Critical Rate at a flat conversion of +1% critical heal rate for every 30 spirit (there is no Diminishing Returns on it). For example, with ~740 spirit you can expect an ~24.7% crit rate which is it is really huge as doing a Healing Crit will save a lot of mana & make your life as a healer way easier!

In this thread, they mention a skill called Invigorated Healing that boosts your critical healing amount by 50%. "There's a passive in Vitalism (Invigorated Healing) which increases heal amount by 50% when "a healing skill goes critical.""

In that same thread, someone confirms that Intelligence only boosts magic and ranged and does not affect your healing, further supporting that Spirit would be your main spec.

• "Zeal specifically mentions a separate increase of healing crit rate."
• "Int[elligence] does not increase heal crit rate, only magic and ranged. If you look at your character sheet, you will notice that your heal crit rate is drastically different from your magic crit rate."