效验的英文：
efficacy

feeling of efficacy
效力感

The efficacy of the medicine is satisfactory.
这药的药效令人满意。

Saturation does not increase efficacy.
饱和剂并不增加疗效。

The efficacy of this intervention has not been determined conclusively.
这种干预的功效尚未最后确定。

Because it has the same efficacy as operative knife.
因为它能起到手术刀一样的效果。