The weekly two-hour PEIL workshop session revolves around a set of problems relevant to the textbook chapter or topic covered in lectures during that week. The two accompanying 110-minute lectures per week, which include recitation time for answering students’ questions, provide a mechanistic scaffold of the knowledge necessary for students to arrive at their solutions by emphasizing the underlying concepts such as spatial orientation, delocalization of charge, and electron flow. However, the workshop questions are of a relatively high degree of difficulty, which encourages or even necessitates group discussion among students in trying to solve them. Attendance at these workshops is optional, so there is no credit or graded assignment associated with them. However, students in a class with a PEIL workshop cannot register for other classes during the workshop time, ensuring that all students can attend if they wish. No additional lecture material is covered during the workshop sessions, and all students have access to the workshop questions, even if they choose not to attend