I found an article yesterday that explains some of the resistance to thinking that I’ve been seeing in my AP Biology students. This is my first year teaching AP Biology, and it’s also the first year of the redesigned AP Biology course. The AP Bio test was traditionally all about brute force memorization for the multiple choice questions, with some application and synthesis tacked on for the free response questions. Starting this year, the multiple choice questions will require much more thought. Here is an example of a traditional multiple choice question:
If plant cells are immersed in distilled water, the resulting movement of water into the cells is called
B) active transport
E) facilitated diffusion
Here is an example of the new type of question:
Paramecia are unicellular protists that have contractile vacuoles to remove excess intracellular water. In an experimental investigation, paramecia were placed in salt solutions of increasing osmolarity. The rate at which the contractile vacuole contracted to pump out excess water was determined and plotted against osmolarity of the solutions, as shown in the graph. Which of the following is the correct explanation for the data?
A) At higher osmolarity, lower rates of contraction are required because more salt diffuses into the paramecia.
B) The contraction rate increases as the osmolarity decreases because the amount of water entering the paramecia by osmosis increases.
C) The contractile vacuole is less efficient in solutions of high osmolarity because of the reduced amount of ATP produced from cellular respiration.
D) In an isosmotic salt solution, there is no diffusion of water into or out of the paramecia, so the contraction rate is zero.
These two questions test the same concept, but at different levels in Bloom’s taxonomy. The traditional question asks the student to recall the definition of osmosis. The new question requires the student to interpret the graph, read ALL of that information, and figure out that the contraction rate increases as the osmolarity decreases to get rid of the excess water that’s entering the cell.
My students DO NOT like the new questions. For the semester final in December, I used 28 of the new multiple choice questions and 1 free response question. The students’ scores were similar to the other tests during the semester, which did not include as many critical thinking questions, but the students were frustrated just the same. A common refrain: “The study guide questions didn’t have anything to do with the exam!” Well, no, I did not ask you anything about contractile rates of paramecia on the study guide, but I did ask you about osmosis and had you draw pictures of situations when water would move into and out of cells. You then had to APPLY that information to answer the question. My students would rather just RECALL exactly what they wrote down on the study guide.
The article I mentioned above highlighted these attitudes from students in a first-year college biology course. The author noted that “students in this class usually struggle with the higher-level MC questions on the exams, and tend to perceive them as “tricky” (on the part of the instructor), rather than challenging (i.e., requiring higher-level thinking skills).” (p. 295) The author was testing to see whether students would learn more critical thinking on tests that only include multiple choice questions, or on tests that include multiple choice and free response questions. The students ended up doing better on critical thinking multiple choice questions when also given free response questions, and the author concluded that students study differently for the two types of tests. However, although they performed better, the students did not like the experience. They thought that “the instructor should ‘just teach biology’ rather than emphasize higher-level thinking skills.” (p. 302)
My overall reaction is that I’m glad I’m not the only instructor seeing these attitudes from students. I hate all the jargon that goes along with Bloom’s taxonomy (my school’s administrators love to go on about “higher-level Bloom’s”), but we do need to encourage students to think more. My AP Bio tests always include free response questions, but this is the first class my high school students have taken that includes higher-level thinking multiple choice questions. My challenge for the spring is to convince the students that science is not about memorizing facts and regurgitating them back on the tests; science is about memorizing those facts and doing something useful and interesting with them.