An expression meaning "from the point of view of" or "in terms of" a particular perspective; used to present a judgment or opinion based on that viewpoint.
経験からいうと、その方法はあまり効果がない。
From experience, that method isn't very effective.
安全性からいえば、この機械は改良が必要だ。
From the standpoint of safety, this machine needs improvement.
年齢からいうと、もう少し休養が必要だろう。
Considering his age, he probably needs a bit more rest.