The biggest reason is not only to make sure your students are where they need to be, but to check yourself as the teacher. I realized, even after our very first Acheivement Test, that I teach every student differently. At first thought, I panicked. I was like on my gosh, I'm not teaching every student the same or equally. But when I really thought about it, I realized that every student is, in fact, different and respond to teaching in many different ways. With this one test, I was able to check my myself to help modify and improve how I teach per student!
My second reason is that not all testing has to scream anxiety. The goal is to remember that you aren't testing for perfection; you're testing for what is known and what may need to be reviewed. In my case, I found that there was A LOT I wasn't reviewing with my students on a day to day basis, and that's okay; it will only make our lessons hereon out more beneficial!
Lastly, testing helps you and your students move forward. Maybe a student missed a lot of the questions, maybe they got every single one correct. Either way, testing provides a basis for where your student is and provides a system to help further their knowledge of music. For example, your student could be in Lesson Book: Level 3, but maybe they didn't understand the content as well as you had thought. It let's you know that they may need to review Leeson Book: Level 2.
**One factor of review that I want to point out is that it's okay to not understand something or not know the correct answer. It is highly important that your students know it's okay to make mistakes, to fail sometimes, fear the unknown, and that going back a book or two to refresh their memory is actually a good thing for brain development. What we don't want is for our students to feel like they can't figure something out on their own, ask questions, or become dependent on others to provide them with the answer. Our goal for each of our students is to provide them with an effective music education that helps them develop the independent skills necessary for every day life!