Assessment is SO important! The teacher needs to CONSTANTLY be accessing the understanding of the students so he/she can go over the concepts that students aren't understanding. Luckily, because of all the new technology available to schools, constant mini quizzes, quizzes, and tests don't need to be made to access students so "formally." There are SO many other formative assessments teachers can use for students, including clickers. Also, the SMART board is a wonderful tool - teachers need to be taught all they can do with them!
http://www.youtube.com/watch?v=r3R6gewJ9xg
Another effective way for teachers to promote interaction between students and assess them as well:
http://www.youtube.com/watch?v=_xeBt-bOK1s
Question-Answer Ball Throw:
http://www.youtube.com/watch?v=nYIrPuxEgcs
Interactive Word Wall:
http://www.youtube.com/watch?v=hoconCtm2tE