When I first began teaching, I hated the unit on electrity. It was boring to teach and I know if I hated it then the kids did too. Several years ago I was fortunate to attend a professional development program on Modeling Physics. This PD changed my approach to many physics concepts but electricity most of all. The entire unit is taught entirely through constructivism. The first thing students did was predict which diagram would light, tested their predictions and then had to arrive at 4 different ways a bulb could be lit using only one wire, one battery, and one bulb. At the end students prepared their whiteboards and presented their lessons to their classmates and had to defend their responses.
The entire unit is based on just that process; the scientific method in practice. From experience, on the test for this unit 90% of students will score 75% or better on the exam and then 5 years from now if you were to ask them questions about this topic they can still answer them. Now, if only the government would get out of my classroom so that I could teach all concepts this way perhaps the world would change.