What are some good ways to keep students coming to lectures? Having taught calculus for several semesters, I've noticed that the number of students attending lectures are gradually declining (especially for the 9am session). I would not be worried if they have learned the material by themselves so don't see the need of coming; However looking at their exam scores I concluded that a lot of them are not doing so well in the class when they miss lectures.

So what are some good ways to keep students coming to lectures?
Here are my suggestions:


Make sure your lectures actually add something to their learning experience. Ask one of your coworkers or someone from the teaching support center (if you have one of those) to come watch a class every now and then and give you feedback on how to improve. (Even if you are a teaching super star, there is always something you can improve.)
Take 5 minutes to ask the students to fill in anonymous "exit tickets" with three questions: Something you should keep doing, something you should stop doing and something you should start doing. This should be done in class after a few weeks, but before the attendance starts dropping. Actually follow any reasonable suggestions.
Over the long term, create a scatter plot of number of lectures attended versus final grade. If your lectures are useful, then there will be a strong positive correlation between the two. Show students the plot during the first class every semester and tell them to make their own decision about attending or not.
If you really want to make them attend class, schedule daily quizzes that account for some not insignificant percentage of the grade. If they don't attend class, they receive a zero.
Remember that your students are adults. They are responsible for their own learning, and if they decide to sleep in rather than come to class no matter what you do, that's still their choice and their responsibility. You can't force them to attend. If your lectures add value, and they still choose not to attend, that's ultimately their problem.