I have read two blog posts recently on the topic of units and themes. Firstly this post from Elementary Observations, in which the writer gives a brief outline against. Secondly this post from Study at Home Mama, in which the writer makes a case for the use of unit study.
In my training, and my mentor was AMI (Bergamo, Italy) trained, I was told that themes do not work. More explicitly that to teach to themes or to only do botany one term and zoology another term doesn't work. It probably works great for the teacher, but our focus is the child.
The beauty of the Montessori 'curriculum' is that it is not necessary to organise and plan in the same way mainstream and other methods do. The learning areas are already laid out - the sequence of key lessons - so that the child is able to make the many discoveries on their own. It is the core objective that the child constructs himself and his learning from his experiences - the key lessons, the cosmic fables and the prepared environment - rather than the teacher imposing knowledge and opinions on the child.
Units and themes are unnecessary because we are giving children the key experiences they need that serve as a launching pad for their exploration and learning.
To me it appears to be a lack of faith in the method to be bringing in mainstream ideas and tools of education into the classroom.
