Hi Zhiwen, I have read through your blog post and I am convinced by your words. I do appreciate your splendid work which introduces me to the basic concept of “SAMR” methods. However, I have some questions regarding your content. In terms of the first paragraph, you explained “ substitution”  and “augmentation” and classify them into one category. However, I was curious about what exactly they are and why they can be categorized into one group.