An Open Thread: a place for things foolishly April, and other assorted discussions.
This thread is for the discussion of Less Wrong topics that have not appeared in recent posts. If a discussion gets unwieldy, celebrate by turning it into a top-level post.
Update: Tom McCabe has created a sub-Reddit to use for assorted discussions instead of relying on open threads. Go there for the sub-Reddit and discussion about it, and go here to vote on the idea.
...and yet...
Probably.
If a 50% chance of having a test that day would leave a student surprised he can be 87.5% confident in being able to fullfil his assertion.
However, if the teacher was a causal decision agent then he would not be able to provide a surprise test without making the randomization process public (or a similar precommitment).
The problem with choosing at day at random is, what if it turns out to be Friday? Friday would not be a surprise, since the test will be either Monday, Wednesday or Friday, and so by Thursday the students would know by process of elimination that it had to be Friday.