I am still working with students on the distinction between speeding up/slowing down and positive/negative acceleration.
I love the modeling approach in that it really gets students to have a real experience with the material prior to any direct instruction problems or lecture.
I gave the students a set of four graph as a “study guide”. I think it is good that they receive this as they feel supported and know what is expected of them.
I need to work on a way of getting them to draw these plots without memorizing them.