Exploring an effective way of teaching physics 2325 and 2326

I have found a seemingly effective way of teaching physics 2325 and 2326. 1. Start class with one or two interesting questions which are closely related to the content of class. 2. Use less PowerPoint but more writing and talking to make the points and keep the lecture going. 3. Leave around 10 minutes at the end of class for a simple class quiz which will be graded. Several years of practice proves that this method can greatly reduce the number of students who play cellphones, increase the number of attendance, reduce the number of dropout, and increase the class GPA.