I allow my students to use a note card on all tests and quizzes. Further
they may use any calculator that doesn't dim the lights. (I teach high
school physics.)
It doesn't take long for students to realize the implication of this
situation. I won't be asking for definitions or equations. All problems
and essays (yes, I give essays) are based on applications of the laws and
equations. They can also expect to see new problems or problems from a
different tack on every test.
The initial euphoria over the note card quickly fades as they realize that
the tests will be different than the ones from other teachers. A few drop
my class right then. (Physics is an elective at my school.)