This is a common case which brings about several questions to consider in the planning stage.
1. How many students per classroom?
2. Access available outside of classrooms?
3. Number of devices a student will have?
4. What map are you using for planning?
- By the sound of it, are you trying to use a campus map? If so, it'd be better if you split the campus mapping. Suggestions could be to divide it into quadrants, or by building(s), or some other logical manner that will make it easier for you to use when troubleshooting. The reason for this is that with the entire campus as a single map, you're going to have less granularity (location approximation is based on grid cell size, larger floor plans do not offer optimum grid cell options), while incurring additional load during placement calculations (means more memory resources dedicated to VRF).
- In this, imagine troubleshooting a client in a specific building. You navigate in VRF to that building, and then can quickly focus on the client. On a global floor plan view, you'd have to zoom in and then try to pinpoint the client out of a mashed cluster of dots (less usable for troubleshooting).
- When determining how to splice the campus, it will depend on how many APs per room. You need at least 3 APs to get good location triangulation, so a floor plan with a single AP is not useful.
- For planning, when you divide the campus up, you should try to keep regions down to below 3, and not overlap regions. This may mean that you may have to draw a region like a single line drawn donut (like drawing the outline of the letter "C") if there's an area in the middle that needs to be excluded from the region.
Opening a support case or discussing further with your SE may give you some additional things to consider. Answering the questions I provided above is just the tip of the iceberg when planning a deployment.