1. efficacy

1. This plan would have some efficacy in preventing any danger.
    这计划对于防止危险会有些效力。

1. 效力：APA判断与衡量最佳研究证据的指标主要有两个:效力(efficacy)与临床效果(clinical utility)[10]. 效力类似于实验心理学中的内部效度,即一个研究测量到其要研究因素的准确程度. 一般说来,随机控制组实验的效力指标最好,

1. 功效;效力
    If you talk about the efficacy of something, you are talking about its effectiveness and its ability to do what it is supposed to.

    e.g. Recent medical studies confirm the efficacy of a healthier lifestyle.
           最新医学研究证实了较为健康的生活方式的好处。

1. capacity or power to produce a desired effect

    e.g. concern about the safety and efficacy of the vaccine

    Synonym: efficaciousness