Setting: High School Biology Class. Spring Semester. My first day back as their Student Teacher since before Winter Break.
time passes
Me: "Can I have a volunteer to read the introduction to today's lab?"
Volunteer reads introduction
Me: "I'm very strict about labs. Paying attention during the pre-lab readings and reading the procedures before you begin is important to me. If I feel that you aren't prepared for the lab, you will not participate. Please read the procedures quietly - you may read to yourself or partner read."
Time passes.
Student: "Can't we just read it while we do it?"
Me: "Not really. The first instruction asks you to write a hypothesis, but without understanding what you'll do during the lab, you won't be able to guess what will happen."
Student: ...
Time passes. All eyes are off the packets.
Me: "Who can summarize the purpose of today's lab for me?"
Pause.
Student: "It's about natural selection of rabbits from genetics and alleles."
Me: "Yes. We'll be seeing how alleles are randomly mixed in populations, and how those genes that are not suited to the environment are selected against. Here's how it will go," picks up paper bag with beads, "In this bag, there are 100 beads, 50 of each color. When I shake it up, that's the bunnies 'breeding.' Then, I reach in and take out two beads. These two beads are a baby bunny that is born. If I draw two yellow beads, it has fur; if I draw a yellow and a red, it's a carrier for the furless gene, but it has fur and will survive; if I draw two red beads, the bunny is born furless and dies before it reproduces. Take the beads, make a tally mark for which kind of bunny it is, and put them in a pile. After all the beads have been taken out of the bag, set the double recessive bunnies aside, they've died. Count how many surviving alleles remain of each color and record the data. Return the beads to the bag, and repeat."
(Okay, to be fair, I meant to say all of that, but found that the students were not paying enough attention and I decided to give up around "put them in a pile.")
Me: "You will work with a partner. Find a lab station, and begin."
There are 7 lab tables, there were 16 stations for this activity. At each table, I repeated the following after seeing how students were progressing:
"There are three questions at the top of your worksheet, including the prompt for the hypothesis. Answer ALL of them before doing the lab."
"Don't count the beads from the bunnies that died. Only count the ones that survive to the next generation."
"Count INDIVIDUALS in one column, and ALLELES in the other column."
"You will always have 50 of the dominant allele - it can't be in a dead rabbit in this simulation."
"The instructions for calculating frequency are in the procedures."
"The procedures clearly said to write frequency as a decimal, not percentage."
How do we get students to read procedures? This was really an incredibly straight-forward lab, with well written instructions (borrowed from another source and I had tested it out several times). Labs are only effective if they find the purpose in them - unfortunately, the purpose is in the procedures, and the procedures are ignored.
