One of my good friends and colleagues, Nick Kowgios, is perhaps the most innovative, thoughtful educator I have ever met.   He developed a method for assessment coined “Test Debate/Test Analysis” where students i.) take a multiple choice test, then, as a class, ii.) debate and vote on the answers to the test, and finally iii.) metacognitively write about choices they made and their impressions they had.  This process is very Socratic and allows the teacher to truly be a facilitator. 

On the surface it sounds very odd. Students vote for the best answers and decide?  Probably would sound even odder if I told you that students have debated one multiple choice question for well over an hour.  However, Nick’s work has demonstrated that this method produce statistically significant increases on standardized tests (AP exams, state exams). 

I’ve used the method, and what strikes me is that assessment becomes more formative.  In other words, we often teach students concepts, learning stops, we assess, and move on. In this format, we teach student concepts, we assess, and learning continues.   The key to the whole process is that assessment MUST be conceptual.  Nick and I were chatting about the application from his discipline (English/LA) to mine (Science), and some of the resistance he has encountered from science teachers.  Here’s part of what I wrote to him:

I would categorize science learning and assessment into three broad categories:

1. factual

2. conceptual

3. analytical

 

Factual clearly being a way where teachers are concerned with isolated facts out of context.  Conceptual as you and I think about it.  In science assessment- more so using big ideas to analyze scenarios and apply knowledge.  Analytical would be more of a computational problem solving approach.  I think of conceptual questions more as ill-defined problems and analytical as well defined problems.  Both are inquiry-based but a conceptual question can have multiple possibilities (i.e., the BEST answer), where a well-defined has one right answer (i.e., the CORRECT answer).

 

Most chemistry teachers use an analytical approach to their teaching, so they might not realize that they have to change the way they assess – they need questions that have best answers instead of questions that have right answers.  (Is my distinction OK and clear?)  Conceptual learning generally works better (easier? less work for the teacher?  less change in philosophy?) in a non-quantitative course like Biology.

 

Today we were doing debate and this question really challenged the kids (about 30 minutes on this one):

 

8. A scientist suspects that the food in an ecosystem may have been contaminated with radioactive nitrogen over a period of months.  Which of the following substances could be examined for radioactivity to test that hypothesis?

a. the cell walls of plants growing in the ecosystem

b. the hair produced by skunks living in the ecosystem

c. the sugars produced during photosynthesis by plants growing in the ecosystem

d. the cholesterol in the cell membranes of organisms living in the ecosystem

e. any of these choices would work well.

 

The context of the question comes from a unit on macromolecules.  We had learned the structure of carbohydrates, lipids, and proteins.  We had not discussed radioactivity in any sense.  They should have had previous exposure to radioactivity, but ultimately, it doesn’t matter too much in the context of the question.  I’ll give my impression on the thought process that should/might happen:

 

First, students have to recognize that nitrogen is an atom and nitrogen makes up only certain macromolecules. (This, by the way, didn’t happen for all students – they got stuck on radiation as some amorphous property that could “drift” from one place to another, instead of being a physical property of the nitrogen atom (i.e., additional neutrons)).

1. carbohydrates are made from carbon, hydrogen, and oxygen

2. lipids are made from carbon, hydrogen, and oxygen

3. proteins are made from nitrogen, carbon, hydrogen, oxygen and sulfur

(4. nucleic acids (DNA/RNA) are made from nitrogen, carbon, hydrogen, oxygen and phosphorus) – I put this one in parenthesis because we did not talk about nucleic acids, and there are no nucleic acids in the choices above).

 

Now students have to decide which of the above might contain proteins (no longer nitrogen)

a. cell walls are primarily made of cellulose – cellulose is a carbohydrate – but there are some proteins that are present.  However, the radioactivity is probably mostly in the plants – however it’s the proteins of the plants, and there’s not very much of that in a cell wall.

b. hair of the skunk is primarily made of protein.  Toxins tend to bioaccumulate, so as you go up the food chain there should be a higher concentration.  I think this is the best choice.

c. sugars are carbs – no nitrogen.  Interestingly, a student quoted a book saying something about radioactivity in the photosynthetic process.  He was quickly slapped by another student who commented that he was talking about radioactive carbon, not radioactive nitrogen.

d. cholesterol is a lipid (steroid) – again, no nitrogen.

e.  they just all don’t work

The class was primarily debating the merits of a and b.  I actually stopped for five minutes to make them do some data hunting for better support – they hit the books and came back, still arguing.  Ultimately the class went for b, because the “a” supporters were having trouble putting holes in the “b” argument. 

 

Notice how much I can write about a multiple choice question.  The students are just as passionate.  And the learning that is taking place is powerful.  Consider the following question.  The students in my class are split over the best answer.  Read the comments and see how they interpret, support, provide evidence, analyze, and synthesize information:

15.  A reasonable conclusion from the Sponge – Bacterial Growth Lab based on class data would be

a. the zone of inhibition prevents bacterial growth

b. Lysol is an effective antibacterial agent

c. pathogenic bacteria grow on Petri dishes

d. a moist, 37^oC incubator is the optimal growing environment for cultured bacteria

e. microwaving a sponge for 1 minute effectively kills bacteria