How is the understanding of the Zone of Proximal Development and the concept of Scaffolding useful to the preschool teacher?

The Zone of
Proximal Development takes into consideration each student's strengths, weaknesses, and
preferences. The ZPD is the stage at which the student is considered "instructional."
Compare this to an independent stage, in which the child has already mastered all of the skills
being presented and can apply those skills without teacher or peer assistance and to the
frustration stage, in which the skills are too difficult for the child to complete with an
appropriate amount of peer or teacher assistance. At the ZPD, the child is ready to learn a new
skill through teacher modeling, several examples of guided practice, repeated independent
practice, and then assessment and follow-up. 

Scaffolding is essential, as
students enter preschool with varying degrees of knowledge about important concepts such as
shapes, colors, numbers, alphabet knowledge, rhyming, etc. Some students may arrive already
counting to 100 and recognizing numerals through 20, whereas others do not know how to count nor
do they recognize any numbers represented in written form. The same lesson will not meet the
instructional needs of both students, as they both are at very different levels of development
(ZPD). Therefore, the lesson can be scaffolded to allow for instructional opportunities that
will leave each child with a successful learning experience. For example, the child who can
already count and recognize numbers could work on counting groups of objects and writing the
numeral that represents the group, while the child who does not have 1:1 correspondence or
number sense would learn to count orally to 10, learning the names of the numbers and their
order. 

Reading is another great example of where the ZPD and Scaffolding is
important in the preschool classroom. One child may not have had many experience with print, and
not know how to hold a book, to retell a story, or recognize any letters of the alphabet. On the
other hand, there may be a student who can sing the ABCs, recognize the alphabet, know letter
sounds and maybe even know some sight words. The first child would be frustrated by a lesson on
blending 3 letters together to read a word, while the second child would be completely bored if
asked to sit through "letter of the week" lessons. Therefore, the lessons would be
scaffolded to allow each child to work at their ZPD to learn something new that is appropriate
to their current level of knowledge.