Psychologists report that children in nine-month schools typically forget a significant amount of schooling during summer breaks.
Conclusion (We should conclude)
The twelve-month schedule is to be preferred insofar as academic learning is concerned.
Intermediate Conclusion
[The twelve-month schedule with three month-long breaks] will insure that students will not forget their schooling during their breaks.
Evidence (on the basis)
Psychologists report that children in nine-month schools typically forget a significant amount of schooling during summer breaks.
Evaluate
Since the conclusion is a Comparison about the academic learning that happens via the 12 month vs. 9 month schedule, we should be analyzing how academic learning is affected in each case.
How could we make the case that the 9 month schedule is better for academic learning?
The author will say that with 12-months, students won't forget their schooling during breaks, as they do with the 3 month summer break.
But what if students burn out, or miss out on cool summer academic opportunities because of the 12 month schedule?
There could be downsides to the 12 month schedule that would offset / outweigh the upside of "less forgetting after a break".
We could also object to the extreme claim that "students will not forget their schooling" after any of their three 1-month breaks. A month is still a decent time away from school and might lead to forgetting.
Goal
Let's look for an answer disputing that 1-month breaks really ensure that students won't forget their schooling, or for an answer saying that there could be downsides to the 12 month schedule that outweigh the upsides.