Techniques for Assessing Course-Related Knowledge and Skills

What I know about assessments:
     I know that there are 2 different types of assessments, summative and formative or formal and informal (respectively). I know that formative assessments are basically just checks for understanding throughout each lesson. "thumbs up if you understand, thumbs sideways if you kind of get it, thumbs down if you need help" .... "give the number 1 if you get it, 2 if you klind of get it, three if you need help" ... things like that. Summative or formal assessments are basically the "tests" or "exams" or even quizzes. Multiple choice assessments DO NOT and I repeat DO NOT show understanding at all!! You can cheat your way through a multiple choice assessment any day of the week. Assessments need to have students explain so you can see, if they are wrong, where exactly they are wrong at!!

What I want to know about assessments:
     Honestly, I cannot think of what I want to know. I've given assesments before and all turned out okay. I guess the only thing I can think of that I would struggle with is if a student refuses to do the assessment or try at all. In STEP TWO I had a teacher allow her students to write IDK (I don't know) on my pretests and then ISDK (I still don't know) on my post test ... how did that help them or me at all???