Unit 2 Reflections: Classification

I really wanted to title this blog post "Phylum Phail," because that's sure what it felt like.

Yesterday, I mentioned I wasn't quite sure when to present students with this tree in the activity:

The cryptic phyla tree, complete with obnoxious copier line

The instructions stated:  give each group a set of animal kingdom cards, group the cards based on similarities, WB groups with justification, hold a board meeting to discuss the significance of the characteristics.  Scientists call this level "phylum."  Repeat grouping with a single phylum.  Hold a board meeting to discuss the significance of the characteristics.  Scientists call this level a "class."

Easy enough.  But where does the tree come in?

I couldn't leave things simple.  I just had to try to use that dang tree.

I kicked the activity off by asking if we could classify species beyond the "kingdom" level, to which the students said yes.  So I distributed the animal kingdom cards.

A sample of some of the animal cards

The students started grouping them immediately.  I had them whiteboard their groups, which tended to be more focused on the taxonomic classes than the phyla. Their groupings included things like reptile, mammal, amphibian, insect, etc.  A popular category was "aquatic" for all the sea-dwelling creatures.  Only a few groups included vertebrate and invertebrate.

In hindsight, I should have latched on to those groups who created a vertebrate category like a rabid dog.  Unfortunately, that's not what I did.

Since the categories were ALL over the place, I distributed the tree of phyla to try to "help" them.  Ha!  I tried suggesting that this tree showed actual groupings.  I tried suggesting maybe they should figure out which organisms go in which group.  I even tried walking groups through the "sponges" category and encouraging them to do the same with other categories they could identify.

Things like the echinoderms, the arthropods, etc. were ok for them.  Very, very few groups made the leap that chordata should include more than amphibians.  I had students trying to put snakes in the annelids, mammals in the lophophorates, and all sorts of craziness.  They weren't seeing the similarities and differences.

There were so incredibly many misconceptions that I could not possibly address them all.  The most frustrating thing is that I could not get the students to THINK about the descriptions on the card.  Sponges were easy, because their descriptions were identical.  But as soon as a single word in the description varied, the majority of students were ready to give up on trying to pair them together.  They had a hard time inferring which similarities were most important to the grouping.

So... how would I revise this activity in the future?  And better yet, how am I going to salvage this tomorrow?  First of all, I'd leave out that dang tree until after the activity next time.  I think this would have gone fine had I not been so worried about including the tree.  It could be very useful in the post-discussion, but I definitely won't ever give it to them during the activity again.  Lesson learned.  Tomorrow, I think I'll just have them pull the vertebrates out quickly and go from there.