As a teacher, I have heard many times…"Oh they learned that in middle school." This statement is always given with the implication/expectation that I don’t need to spend as much time on a particular topic because students were taught this previously. I hate this! I cannot afford to plan my chemistry lessons as though the stars have aligned in the lives of the 150 students randomly placed in my classroom.
What do I mean by this?
Assumption #1: To assume my students walk in with chemistry knowledge to my classroom, I must first assume that a chemistry topic was taught. I have to assume that not only did a student's middle school teacher teach a particular topic (they didn't run out of time at the end of the year), but also that the state/school district required a teacher to teach that particular topic.
Assumption #2: I have to assume the teacher taught the topic well and in an easy to explain manner. No offense to teachers out there, but most of the time when I meet people who don’t actually teach the full high school chem course, the teachers don’t know the material (or at least don’t know the tips and tricks I teach my students). That’s just not their area of expertise.
Assumption #3: I must then assume the students were present for these lessons. When chemistry is taught at lower levels, it is often just one unit in the science curriculum. If a student had the flu, they could miss learning a large chunk of the information.
Assumption #4: I must then assume that the student learned it and passed the unit.
Assumption #5: I must assume the student correctly remembers all of the information they learned.
Really...the stars aligned so that all 5 assumptions are true for the 150 students in my classroom? NO. This just isn’t reality.
Don't be discouraged. To me this should not be a point of frustration or irritation for a teacher but rather a practical acknowledgment that students need to be taught everything. Assuming prior chemistry knowledge can be fraught with pitfalls. In my classroom, I choose to work from the position that my students know nothing when they enter my chemistry class. I teach it all from the simplest to the most complex topics. Sometimes...yes, the class breezes through a particular topic due to previous learning. Most of the time...that specific instruction is needed and helpful.
The moral of my story here is to never assume your students have chemistry knowledge!
Teach it all from the simplest to the most complex. You won’t regret it!
Happy Teaching :)
- Founder of Chemistry with Confidence