I am a physics lab TA and I was recently informed that my engineering students will receive a lab final at the end of the semester worth 50 percent of their grade. The final exam is not personally created by me, but is decided amongst all of the lab TA's teaching the same course in the same semester. The meeting amongst the TA's will occur next week, however I am attempting to prepare for whatever will come, for better or worse for my students. I want my engineering students to succeed, and I want to give them all of my resources to give them the preparation to pass the final exam. I assume that I will not be allowed to tell my students what the lab final will be, or what types of questions will be asked. My students are required to complete 9 weekly lab worksheets corresponding to their specific lab of the week. All sum total of all lab worksheets are worth the other 50 percent of the lab grade.
One issue I am currently weighing in my head is how to grade the lab worksheets. Should I go easy on the grading to soften the blow of the final exam, or should I grade harshly to force them to correct every mistake they make in prepration for the final exam?