After reading about the curriculum on the web, I find it quite interesting. The curriculum was developed in the 1990s, and it was developed with support from the National Science Foundation. From their website, I learn that the Investigations in Number, Data, and Space (which is the official name of the curriculum, it appears) was designed to:
- Support students to make sense of mathematics and learn that they can be mathematical thinkers.
- Focus on computational fluency with whole numbers as a major goal of the elementary grades.
- Provide substantive work in important areas of mathematics—rational numbers, geometry, measurement, data, and early algebra—and connections among them.
- Emphasize reasoning about mathematical ideas.
- Communicate mathematics content and pedagogy to teachers.
- Engage the range of learners in understanding mathematics.
The guiding principles underlying these goals are that students have mathematical ideas, (…) teachers are engaged in ongoing learning about mathematics content, pedagogy, and student learning (…) and that teachers collaborate with the students and curriculum materials to create the curriculum as enacted in the classroom (quoted from their website). In many ways, the Investigations curriculum appears to have some common underlying ideas with the Everyday Math curriculum (which has also been strongly criticized by some). According to several impact studies, the Investigations curriculum appears to have a positive impact on the achievement of students, and Everyday Math is also a curriculum that is strongly based on research. As someone standing outside of this debackle, I am therefore somewhat amazed by the criticism these curricula has raised. Somewhat, but maybe not all that amazed after all. Our previous Norwegian curriculum (called L97) featured some of the same ideas about teaching and learning of mathematics, with a focus on letting the students discover and reinvent the mathematical ideas, having “mathematics in everyday life” as a main area of the curriculum, etc. After less than 10 years of implementations (evaluation reports showing that the curriculum had not really been implemented in the classrooms), it was replaced by a new curriculum called “Kunnskapsløftet” (Knowledge Promotion). This curriculum has a much stronger emphasis on basic skills, little or no mention of discovery and reinvention, little emphasis on connections with everyday life, etc. So, I guess this debate is not only typical for the US and in this case Loudoun county.
For me as a researcher, I think it is interesting to see how much resistance these “reform curriculum” efforts encounter, and it reminds me of something I read in The teaching gap. Teaching of mathematics appears to be some kind of cultural entity, and I think Stigler and Hiebert used the notion: “cultural scripts”. In order to implement a new curriculum, it is often necessary to change some of these cultural scripts, and that appears to be a rather cumbersome endeavor…
P.S. If any of you has some references to research, articles, etc. that relates to the above mentioned curriculum papers, please let me know!
Reidar Mosvold 
I have taught Investigations for more than 7 years. My district is just adopting it this year. What I notice is that it is challenging for teachers and parents to wrap their brains around. When we are first teaching the curriuclum we are moved out of our comfort zones of "knowing math". Because we haven't been trained adequatley in how mathematics develops, we can't articulate that to parents. It is hard to be in a profession and suddenly feel like you may not know what you are talking about. With this said, I have become a much better math teacher in this process. My children love it and engage in it deeply. Test scores are driving a great deal these days, but for years we have been graduating children with high test scores who do not measure up in college. Change is hard and has well defined stages of development. As a nation we are is the beginning stages of change "anger" and "denial". When we move on to acceptance about our current situation we will begin to make progress. Specific research can also be found on TERC's website regarding longitudinal studies conducted in the northeastern region of the country. I am familiar with the work done in Louden county and Texas and both situations had good intentions. Implementation is a long slow process that requires deep planning and tons of support for teachers. No one curriculum meets all of standards of any one state. It is up to a district to put all necessary supports in place before making a shift. Prince William County has done a great job. Like with every county/state in the U.S. you will find the few exceptions to the rule but in general they are reaping the benefits of stronger mathematical thinkers.
Thanks a lot for sharing! It is interesting to learn about your experiences with Math Investigations!I very much agree with you that no one curriculum framework is perfect, and change is indeed hard! Thanks again for sharing your story :-)-r