Firstly, 270 words would have been a typical High School limit for me, and thus that seems reasonable to me in this case.
However, choosing an appropriate word count depends on a lot of factors. There's the level: High School and Masters students are expected to demonstrate different breadths of knowledge. There's also the focus of the curriculum. (By this I mean, for example, that the detail in which given historical events are studied changes from country to country.) But most importantly, the purpose of the assignment. I expect that an assignment purely meant to test comprehension would be somewhat longer than an assignment testing the skill of synthesis itself, but shorter than one where conciseness is not itself the point.
Students asked to "Devise and document an experiment to measure Earth's surface gravity." (which I was asked to do in High School) will (should) be rated on understanding, experimental procedure, and perhaps critical thinking, but it seems counter-productive to overly restrict length, here. To return to the context of the post, this could be the basis of a later exercise in communication, focusing on clear, concise but accurate summarisation of the findings (but I'm, sadly, unaware of any school that teaches that).
Firstly, 270 words would have been a typical High School limit for me, and thus that seems reasonable to me in this case.
However, choosing an appropriate word count depends on a lot of factors. There's the level: High School and Masters students are expected to demonstrate different breadths of knowledge. There's also the focus of the curriculum. (By this I mean, for example, that the detail in which given historical events are studied changes from country to country.) But most importantly, the purpose of the assignment. I expect that an assignment purely meant to test comprehension would be somewhat longer than an assignment testing the skill of synthesis itself, but shorter than one where conciseness is not itself the point.
Students asked to "Devise and document an experiment to measure Earth's surface gravity." (which I was asked to do in High School) will (should) be rated on understanding, experimental procedure, and perhaps critical thinking, but it seems counter-productive to overly restrict length, here. To return to the context of the post, this could be the basis of a later exercise in communication, focusing on clear, concise but accurate summarisation of the findings (but I'm, sadly, unaware of any school that teaches that).