Most chemistry labs are of the "cookbook" style, the labs are a series of steps to perform in the alloted time and not much thought goes into the performance. The other option is to give students a problem to solve and then give them free reign to design a lab. Many of the students have no idea where to begin the design phase of a lab and end up just looking up a cookbook lab and trying to make it work. The other problem with the free reign option is safety and logistics with the laboratory prep. Is it a safe lab? Do we have the chemicals, glassware, equipment? This is why so many of the colleges and universities go to prescriptive lab experiences.
Our solution is to have a prelab for each lab. The prelab consists of a writing assignment the student must perform before they get into the lab. This writing assignment will help them understand what they are trying to accomplish.