The Three-Period Lesson is a technique used to introduce and consolidate vocabulary and concepts through a structured process of association, recognition, and recall. Adapted by Maria Montessori from the work of Édouard Séguin, it involves linking a sensory perception with its name, recognising the object when it is named, and later recalling and naming the object independently. This approach supports clear understanding, precise language acquisition, and confident recall, while respecting the child’s natural learning process.

“I have found that Séguin’s method for obtaining an association between an object and its corresponding term… is also very useful… He divided the lesson into three stages and we have adopted this same practice in our schools. First Stage is the Association of the Sense Perception with Names, Second Stage is The Recognition of the Object Corresponding to the Name, Third Stage is Remembrance of the Name Corresponding to the Object.” (Montessori, Maria, The Discovery of the Child, p. 168)