|But Mr. Lipshutz, you didn't tell us|
which graduated cylinder to use!
Confusion generally reigns, though, until teachers actually try out a couple of my experiments. The issue? "What do you give to the students so they'll know what to do? Do you have the lab handout?"
My answer is, I give the students nothing. I demonstrate the use of the equipment -- moreso early in the year than later in the year. I tell the class what to measure and how to measure it. On the board, I draw the graph (always a graph) that they should make. That's it.*
But how will the class know what to do?
First of all, they LISTEN to me. If they know a handout is coming, why should they listen actively to anything I say? "I'll just read the handout," they'll think.
Secondly, I don't want students blindly following directions. Figuring out how to measure something is an experimental physics skill, even at the most basic level of "how are we going to find the volume of this water?" Recognizing that they need a graduated cylinder rather than a beaker, then selecting an appropriate cylinder from the shelf, then realizing that the one they chose was too big -- all that is a learning experience. My placing the proper-sized cylinder on the lab table and writing "pour the water into the graduated cylinder and read from the bottom of the meniscus" teaches the class to follow directions, nothing more.
And finally... how many times have you handed out a carefully-prepared lab sheet, then had ten students ask a question to which the response is, "Look at the handout here."? Students DON'T READ LAB HANDOUTS CAREFULLY. We all know this. So instead of wasting time preparing a handout, then getting frustrated, then complaining about how these dang kids today don't read anything... just don't give a handout. Laboratory isn't the time to be teaching the skill of following written directions, I don't think -- that's for homework, tests, and home ec class.
I know you're skeptical. After all, your teachers all through high school and college probably never failed to hand out a lab sheet with complete instructions. It's not easy to let go of this crutch. But flying by the seat of your students' pants in lab does work beautifully. Joshua Beck, who attended my workshop at NC State University last summer, says not giving a procedural handout on lab days "has been great, for me and them." He's right. Try it.
* Sure, early in the year I make sure everyone is acquainted with my lab requirements, as shown here. These aren't on a handout, they're just oft-repeated guidelines.