Johnstone's Triangle

Recently, I asked my students to draw a particle-based model that accounts for the observed increase in pressure when a syringe full of gas is compressed. As they began, one student said, “why do you always make us draw particle diagrams?”

Along my teaching journey, I started to incorporate more inquiry and modeling activities into my classroom at the expense of practice problems “drilling” concepts. Based on student survey feedback, I learned my students missed these drilling activities. They were craving practice they needed to master and get comfortable with the content.

Happy New Year from one of your overseas colleagues. Despite the amazing political changes, the language of chemistry continues bind us together, usually in the effort to make such a simple subject as chemistry understood! To do this, many of you have focused on the triangle developed by Alex Johnstone.

I spend a lot of time working with models in my classroom - developing mental models, drawing models, talking about models, testing models - you get the picture.  As I was planning my school year last summer, my colleagues and I started thinking about how our students interacted with the models.