The dough just hits the sides of the bowl. What should I do?

This is usually due to the dough being too firm and to too much flour being added. Reduce the speed and adjust the base knob. When you make dough in the Assistent, you usually need a little less flour than indicated in the recipe. So add the flour a little at a time. Also bear in mind that the dough gets firmer once the Assistent has kneaded it for a few minutes.