I think because on a test they can't win or benefit from leaving an answer blank, but they can "win" a bit by guessing.
Now if say they are penalized for guessing -- they they pick A and then later asked to explain but they fail and get points taken off for example. Then guessing might be discouraged.
Another reason could be that maybe teachers believe that a student somehow knows the answer subconsciously and just guessing will tease that out. Or not trying to guess, means they have given up and are not engaged. Like say they don't answer, and leave a space blank, maybe to a grader it looks like "this person is lazy and don't want to work".
Anyway, you can interpret that in many ways.
When teaching though, I agree, that should be discouraged, but in a crucial end of the year standardized test it makes sense. And I guess our whole education system has shifted to "teaching to the test" then it makes to just practice tests all the time and not even bother "teaching" for knowledge's sake.
Now if say they are penalized for guessing -- they they pick A and then later asked to explain but they fail and get points taken off for example. Then guessing might be discouraged.
Another reason could be that maybe teachers believe that a student somehow knows the answer subconsciously and just guessing will tease that out. Or not trying to guess, means they have given up and are not engaged. Like say they don't answer, and leave a space blank, maybe to a grader it looks like "this person is lazy and don't want to work".
Anyway, you can interpret that in many ways.
When teaching though, I agree, that should be discouraged, but in a crucial end of the year standardized test it makes sense. And I guess our whole education system has shifted to "teaching to the test" then it makes to just practice tests all the time and not even bother "teaching" for knowledge's sake.