Unit 1 Reflections: Goldfish Lab

$0.15 each at Petco

The teacher notes for Unit 1 give some good suggestions for open-ended lab activities: environmental conditions vs. seed germination, salinity vs. brine shrimp development, temperature vs. goldfish mouth opening, and an isopod choice chamber experiment.  The notes suggest doing a minimum of two of the four labs.  I chose to go with the fish and seed labs mainly due to timing and the availability of materials on hand.  No time to order (and receive) new supplies at the beginning of the year!

The seed germination and brine shrimp labs need to run at least overnight, if not longer.  I wanted my students to get instant feedback on their first attempt at experimental design-- this made the goldfish lab seem like the more logical choice to begin with.  It still took about 1.5 to 2 blocks to complete everything and create a model for experimental design.

Something we utilized in the chemistry modeling workshop that I didn't notice in the biology curriculum is the assignment of lab roles.  We received a great handout defining the four lab roles in a group:  lab manager, recorder, technician, and gopher.  I assigned lab roles beginning with this lab, and let me tell you, I am loving it so far.  I have always heard of doing this, and had even tried to assign "jobs" in the past without much success.  The four role system is really well defined and easy to implement.  The kids took to the roles like fish to water (pun intended) and it has GREATLY reduced chaos in the lab.

We started this lab with each group making simple observations of a goldfish in a beaker.  I placed some basic tools around the room for them to use if they wanted:  a hand lens, a ruler, a thermometer.  Students had a set amount of time to make their observations, then white board the results.  Upon sharing the white boards, I had the students classify everyone's observations by type, then try to break those types down into two categories.  Pretty much all of the classes nailed it and immediately divided the observations into quantitative and qualitative.  All I had to do was introduce the actual terms.

When talking about our observations, someone from every class brought up the mouth opening behavior, making my segue into the problem super easy.  The hardest thing for me to do was step back an let them make mistakes with their design.  First day, first class I caught myself prompting one lab group into creating a control... I didn't even realize I did it until talking with a second group!  It actually made for great discussion in my standard biology class to have some groups with a control and some groups without.  My honors classes on the other hand... yeeeeaaaah, they all knew right off the bat that they needed a control, constants, etc.  The lab was more of a review activity for them, but good for me to assess their knowledge base.

Fish in a beaker submerged in warm/hot water bath

Something useful during the board meetings:  one class' board meeting was cut short by the bell, so I took pictures with my phone and pasted them into a document on my computer.  Not only were the pictures helpful when continuing the discussion the following day, but I've used that document a few times in the days since as we revisit the topic of graphing data.

Verbal, Graphical, and Diagrammatic. Not all groups had the same results.

As the days have progressed, I'm becoming less and less of a fan of the consensus models for experimental design that we developed in my classes (especially the standard class).  First, I'm letting them get stuck in "list" mode-- this would probably work better in a mind map.  Secondly, it needs to go into more detail. The honors classes have stronger critical thinking skills, so the weaknesses with our models have not hindered the students' understanding much.  But I waaaaay over-estimated the critical thinking skills of some of my standard students, and now I've watched them continue to struggle with experimental design, and the model does not provide them with enough to fall back on.  I intend on revisiting and revising the model after our seed germination board meeting, which I suppose should be part of every model deployment anyway!

An example of the model I have grown to dislike