Celia's work is focused on programs to toddlers develop a vocabulary that will set them up for success in kindergarten. she spends a considerable amount of time conducting research and gathering evidence to determine the of various program methods.

Efficacy

Explanation:

Efficacy is defined as the ability to produce a desired or intended result. Celia's focus is to determine the ability of certain programs to produce a desired result, and that is to develop a vocabulary that will set them up for success in kindergarten.