“A teacher must busy herself with finding more and more new names to satisfy the insatiable demands of her young charges. This craving which is manifested in their writing is certainly natural. Between the ages of three and five a child's vocabulary grows spontaneously from three hundred to three thousand or more words.” 

DR. MARIA MONTESSORI

It's during the first plane of development that you may hear a Montessorian use the term, "Three Period Lesson".  The Three Period Lesson is the way in which all vocabulary is introduced to a child during their primary years. This method of vocabulary presentation allows the adult to really understand what the child understands.  The child is presented with three new pieces of vocabulary at one time.  This could be a sound, color, continent, name of a fruit or sight word.  We will use the primary colors as an example in this Three Period Lesson:

First Period

The directress introduces each of the colors and names them individually.  "This is red." "This is blue." "This is yellow."  It is during the first period the child is learning the name.

Second Period

The directress gives the name and the child must choose the correct item. "Can you find red? "  "Where is blue?"  During this second period many games can be played as the child tries to remember each item.  You could also ask the child, "Bring me red." or "Put blue next to the chair." The child may be on this period for some time before introducing the final period.

Third Period

In the third period, the directress asks the child to recall the name of the item.  She may ask, "What is this?" as she points to the red tablet. Once a child completes the third period of the lesson and can recall each name, the directress knows he has mastered this vocabulary.   

Not only is the the Three Period Lesson a great way to gage a child's understanding and knowledge, it can easily be implemented in the home environment.  The second period can be particularly fun as this period is where games can be played.  For example, a parent wanting to practice number recognition could chose three numbers to work with and give a Three Period Lesson.  Once the names of the numbers are introduced, the second period can begin.  The three numbers could be hidden in the living room. Ask your child, "Can you find nine?" or "Bring me seven."  "Put eight on the counter."  The child will be giddy during the hunt for these numbers!