I think the crucial question for each of us is to determine what are the crucial ideas in each topic and somehow find out if our students are learning them at our pace. The great danger in a student centered classroom with activity sheets is that the students (and teacher) will have a great time doing the activities but not build up real conceptual knowledge about what they have done.
Steps I have taken to try to eliminate this problem:
1) Made them aware of the point I just made above at least every other day for a while.
2) Each student must have a notebook with an outline of each topic and some listings and or discussions of each vocabularly work/major concept.
3) Homework assignment sheets lead off with a couple of probing questions to show them what I mean. For instance, I asked:
I assume you know when a bar graph is more appropriate than the dotplot and visa-versa. Can you explain why! The next day most students had a gut sense of the answer but were unable to put an answer into acceptable form ..in other words...they were unable to pass a test on this point. One student was able to explain the answer using the terminology that they had already covered in the book...I hope the rest got the idea. The idea is the activities just get you started. Then you have to LEARN the material
Helpful idea: My wife is a doctor. She often has to read material and then use a new technic or make a decision about the care of a patient using the material the next day. She reads and learns material in a different way then we often do. She MUST really understand what she reads. She must think about the new ideas within a context of what else she knows about medicine. She must develop a vocabulary that is part of the accepted terminology and has meaning to her peers. I suggest to my students that learning statistics this not a life or death experience, but if we thought about learning as my wife does we all would be much better prepared.
4) Send some time each period pulling some ideas together. - For instance I had them all line up by height and then they asked them to physically (without counting) determine the person with the median height. I then had the tallest person stoop over and said that this person is actually now very short. How would that alter our answer (watch out on this one - I faked myself out). Then maybe have the shortest person "get shorter".
5) Assign short readings in BPS (they each own a copy) and the texts on reserve at the library and ask them to compare the presentation in these resources to those in WS.
Disclaimer...Am I getting all this done all the time....In your dreams Coons.