I can't speak from the parent side, because mine aren't in an MYP program, but I think I know where the admin is coming from, since I've taught the MYP science classes (all of them, from grade 6-10). The way the program is set up is different from the diploma program, which is the gr 11 and 12 program that it seems you were in. In the diploma program each class has very different requirements and are graded very differently.
MYP, when done correctly is a standards based program. Standards based means that there are standards (levels of achievement) that the teacher grades everything against. Assignments are only given that appropriately fit into the grading categories for each particular class(math, science, english etc.). It gets rid of the "assignments for assignments sake", every assignment given should have a purpose and be written in such a way that the students are able to reach the highest standard of the rubric. Science assignments, for example are graded out of 6 points, with grade barriers of 0, 1-2, 3-4, 5-6. The levels and standards are provided by the IB organization for the final year of the program (gr.10) schools then break them down to be appropriate for the younger grades, being sure that they are working toward the final standards provided. (This is of course where things can fall apart - if the school doesn't break these standards down well, then the younger levels of the program do not grow as they should to be ready for the level expected by grade 10.) Are your high schools then adopting the program for grades 9 and 10 so that the kids get the full program? If not, then there will be no real understanding by the teachers of where the kids need to go.
How this will help teachers deal with heterogeneously grouped classes? Well, since the standards based grading is not based on percentages right versus wrong, it can allow for more diverse assignments and differentiation within a classroom. I say can because, as is true with any complete curriculum change, it requires the teachers be trained in the MYP program, in standards based grading, and that the district have an experienced MYP coordinator who truly understands how all of the pieces fit together.
I loved teaching in the MYP program, and we are actually looking for an myp school for DD8 to attend because if it is done well, it would be a good fit for her. There should be a lot of cross curricular/project type work, along with integration of social conscientiousness and differentiation.
One thing I would be very concerned about is if the support for the teachers is not there, (in terms of training and an experienced coordinator) then I have also seen how horrible it can be. MYP is a program shell with recommendations of the curriculum to be followed. It is not the typical American set up of giving the teachers everything they need to do in one book with lesson plans and everything else done for them. It requires a ton of work to convert your already existing curriculum to fit the IB model of doing things. (This is what I did the first year I taught MYP - it almost killed me, but was well worth it.) You can fudge it so it looks like you are doing MYP, when you are really doing no differently than you have always been doing and because IB doesn't look at student work until the end of the program (in gr 10) there are no checks the school has to go through to ensure that they have implemented the program properly at all levels. The other thing that is really needed is that the report cards for the kids should no longer be the standard F = 65%, D = 66-69, etc. When done correctly, the MYP is not on a scale of 100, but rather a scale of 0-7, similar to the 0-7 scale of the diploma program.
I do not know if this has answered your question, but I hope it was helpful to you. Again, I would put my DD in an MYP program that was done correctly.
