One method of assessment can be done as you teach. Observing student body language (are they slumped in their chairs or sitting up straight; are they making eye contact; do they take notes when you make improtant points) can clue you in to how much they are paying attention. The number and speed of hand-raisings when you ask a question provides a similar measure. The advantage is that, if you find you have lost the students, you can stop and reteach immediately, rather than waiting unti you mark the test a day or more later.
