Thursday, April 21, 2011

The Student-Centered Classroom

A large part of the AAAS document, Vision and Change in Undergraduate Biology Education is devoted to how to teach science. The "core concepts" take up only 2 pages out of 79 pages in the booklet.

The modern buzzword phrase for the 21st century is "The Student-Centered Classroom" and "Student-Centered Learning." The terms means lot of different things to different people but the key concept is to move away from lecturing about "facts" to a classroom format that emphasizes student participation in the learning process.
Although the definition of student-centered learning may vary from professor to professor, faculty generally agree that student-centered classrooms tend to be interactive, inquiry driven, cooperative, collaborative, and relevant. Three critical components are consistent throughout the literature, providing guidelines that faculty can apply when developing a course. Student centered courses and curricula take into account student knowledge and experiences at the start of a course and articulate clear learning outcomes in shaping instructional design. Then they provide opportunities for students to examine and discuss their understanding of the concepts presented, offering frequent and varied feedback as part of the learning process. As a result, student-centered science classrooms and assignments typically involve high levels of student–student and student–faculty interaction; connect the course subject matter to topics students find relevant; minimize didactic presentations; reflect diverse aspects of scientific inquiry, including data interpretation, argumentation, and peer review; provide ongoing feedback to both the student and professor about the student’s learning progress; and explicitly address learning how to learn.
This is a very good idea in theory but putting it into practice is much harder than it looks. I've seen some excellent examples of student-centered learning at various conferences over the past few years. One type of student-centered learning seems particularly attractive to me and I've tried it several times in my courses. Here's how it's described in the Vision and Change document (p. 26).
Typically, these strategies engage students more actively in every aspect of their learning and are interactive, inquiry driven, cooperative, and collaborative, allowing students to engage with each other and with faculty. For example, the “problem–based model of instruction,” or learning cycle (Bybee, 1997; Fuller, 2002), revolves around a series of related questions that first probe what students know about a topic and then move to unfamiliar, new ground, enabling the students to develop a more complete and accurate understanding of the topic. Faculty initiate student interactions with key guiding questions and opportunities for discussion, present a short explanation of the necessary background knowledge, and then have students work together on questions to deepen their understanding through reflection on and application of their knowledge (e.g., Ebert-May et al., 1997). This approach incorporates frequent informal assessment (e.g., Angelo and Cross, 1992) to address misconceptions and provides a balance between direct instruction and student interaction. One or two class sessions using this approach to introduce a topic such as evolution might unfold in the following way (e.g., Ebert-May et al., 2008):
  1. Engagement Question: For example, “What is evolution?” This background question probes student knowledge of the topic.
  2. Exploration: Students share their answers with other students sitting nearby and come to a consensus; volunteers from the groups share their answer with the class, allowing the instructor to listen for misconceptions and depth of understanding.
  3. Explanation: The instructor presents a short interactive lecture (15 minutes) on the topic, providing explanations to help clarify student thinking based on identified misconceptions.
  4. Extension Question: Students work together on a more advanced question that might, for example, call for them to analyze information, formulate critical questions and hypotheses, evaluate and criticize evidence, or propose alternative solutions. In the example of evolution, the extension question, tied to a learning goal, might be What mechanisms are involved in natural selection, and what role does natural selection play in antibiotic resistance in bacteria today? Again, groups are called on to explain their answers and how they came to them.
  5. Quiz Question: The final assessment (which may or may not be formally graded) allows both the student and the instructor to chart the effectiveness of teaching and learning.
The idea here is to confront misconceptions by having students come up with their own ideas about answering the "engagement question." This gives the instructor the opportunity to correct the most common misconceptions. In this example, the students will almost certainly come up with a definition of evolution that requires natural selection and excludes random genetic drift. They will frequently include mutation and recombination as part of their definition. Most of the time students will demonstrate lack of knowledge of population genetics.

The lecture component will explain the reasoning behind different definitions of evolution and why one might prefer one definition over another. Part of the explanation involves creating a "minimal definition" of evolution that will allow one to distinguish between evolution and something else. (I choose human examples. Think about the increased height in Europeans over the past 500 years. Is that evolution? Why or why not? Why do some native North American populations have only O-type blood? Is that evolution?)

The "extension question" should be designed to challenge students to think about the topic in new ways. In my case, the extension question is often something like this ...
If evolution is defined as a change in the frequency of alleles in a population and if fixation of alleles can occur by several different mechanisms, then what is the most common mechanism of evolution according to the data we have?
I think the three most important criteria in science education are (1) accuracy, (2) accuracy, and (3) accuracy. Everything else is of lesser importance, including how you teach the concept. Thus, you may be an expert at student-centered learning but if you don't understand evolution then the exercise is completely ineffective no matter how much the students may enjoy it.

If we are going to fix undergraduate education in biology then we need to concentrate above all else on making sure we accurately identify the core concepts and make sure they are being taught correctly. We can move on to other things once we are convinced that the first three objectives (accuracy, accuracy, and accuracy) are being achieved. It could actually be harmful to develop a student-centered learning course based on false concepts.


23 comments :

  1. It didn't work in the 20th Century, why should it work in the 21st?

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  2. "The "extension question" should be designed to challenge students to think about the topic in new ways."

    Perhaps students should be introduced to the ideas of those who are challenging current evolution thinking.
    That would be an excellent way to challenge students to think about the topic in new ways.

    Or should students be encouraged to think about the topic only in approved ways.

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  3. I teach physics in high school, so of course am familiar with "Student Centred Learning" (SCL). You are right that it doesn't matter how one teaches if the concepts taught are incorrect. But I do not think SCL was designed for good transmission of ideas, although it can work, rather it was designed to minimize the need for good teachers and to deemphasize the value of knowledge (which is what the definition you quoted said) in favor of entertainment - education is now a product and the consumers need to be happy (not educated)

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  4. Larry,

    I understand that not all changes are necessarily adaptation, but doesn't natural selection play a role even in the case of random genetic drift, in that any new traits that are distinctly maladaptive will usually be less likely to be passed on? It seems to be practically a tautology, as "that which reduces the likelihood of reproduction" seems a fair definition for "maladaptive trait". This is an honest question, not rhetorical. I'm a lay person just trying to understand it better.

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  5. @William K,

    Very detrimental mutations will not survive long in the population due to negative selection. There are many mutations that far into this category. We never see them.

    Very beneficial mutations will often take over in the population (become fixed) due to natural selection. Those kind of beneficial mutations are exceedingly rare. Drug resistance in bacteria is one example.

    Everything else is subject to smaller selective pressures and influenced by random factors. Slightly maladaptive alleles will most likely be eliminated but there's a significant chance they will actually become fixed in a population, eliminating a beneficial allele. The process by which this happens is called random genetic drift.

    Whether or not a slightly maladaptive trait become fixed depends, in part, on the size of a population. In small populations the effects of natural selection become negligible for small differences in fitness—such alleles are invisible to adaptation and their fate is controlled entirely by random genetic drift.

    A lot of evolution took place in small populations and a lot of change is due to alleles that are neutral or nearly neutral in such populations. Natural selection has very little to do with fixation of those alleles.

    (Note: random genetic drift also plays an important role in large populations. It just that detrimental alleles are less likely to become fixed.)

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  6. Students should be challenged to think about the topic in new ways.

    Perhaps students should be introduced to the ideas of those who are challenging current evolution thinking.

    That would certainly challenge students to think and to think in new ways.

    Right?

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  7. Anonymous writes:

    Perhaps students should be introduced to the ideas of those who are challenging current evolution thinking.

    That would certainly challenge students to think and to think in new ways.

    Right?

    Yeah, but after they've disposed of all those arguments, there's still the problem of what to do for the remaining 45 minutes of the class period.

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  8. Jud, is probably like most people here, who do not know the current thinking about the flaws in current evolution theory thinking.

    You are not aware of those objections and have no interest in finding out.

    I have already mentioned the work of Dr. Shapiro and he is not the only one.

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  9. Anonymous,

    Perhaps students should be introduced to the ideas of those who are challenging current evolution thinking.

    If you are thinking about creationism and its barely disguised incarnation as ID. A few times I show my students one or two of the IDiot's arguments and challenge them to find the problems with those arguments. Nothing like dismantling bullshit to show that you do understand. They learn why it is so important to get your concepts right, and why to pay proper attention, and it does not take too much time. I don't do this frequently because we have better things to do. But when I perceive a misconception that could be fixed this way. I do it. Is this what you were looking for?

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  10. Negative Entropy, can you give an example or two of the ID concepts you discussed with your class? And how you dealt with them?

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  11. @Gary,

    SCL was not designed for the "transmission" of information. Rather, its goal is transaction or transformation.

    Student-centred learning requires a better teacher; it is not designed for those poor ones. It requires more effort, greater skill, and more interaction between the teacher and student.

    It's not designed to take away emphasis from knowledge; it's designed to engage students so that they understand the value and context of the knowledge, as well as giving them an opportunity to manipulate it and interact with it.

    I highly recommend you read some Freire or Dewey or Whitehead. They would argue that you are such a product of your education system that you haven't got the skills that their education system emphasizes.

    http://en.wikipedia.org/wiki/Hidden_curriculum

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  12. Larry,

    Thank you for taking the time to address my question. Your explanation was helpful.

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  13. Negative Entropy, can you give an example or two of the ID concepts you discussed with your class? And how you dealt with them?

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  14. @Anonymous,

    I did not deal with them. the students did that themselves by finding the problems. I did not give any help at all. For instance, they were able to easily notice that the "evolution" described by creationist-IDiots with luck might merely have a couple words in common with actual evolution and/or evolutionary theory (and the word "evolution" would be one of them, unless bastardized into "evolutionism," then only one word and a half would have anything in common with actual evolution). The students also easily notice the effort at portraying an ad hoc definition of information that the creationist-IDiots use and move as convenient for mere rhetorical purposes (yes, IDiots constantly move their definition and seem to disagree with each other). Again, I have done this only a few times. I don't want to change the course into a discussion about quackery in nowadays society. That would be better off as a theme for social sciences.

    Once again. I know from experience that you will not do anything else but complain about something else. But I can only tell you that if you educated yourself properly, you would see creationism/ID as quackery with the same ease as I, and my undergrad students, do.

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  15. I had suggested that:
    "Perhaps students should be introduced to the ideas of those who are challenging current evolution thinking.".

    From his post, we can can see that Negative Entropy did not do that.

    At a minimum, a conscientious teacher would have to introduce the research and ideas of people like Dr. James Shapiro.

    Instead, Negative Entropy makes this it into an "us versus the ID people".
    What a pity.

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  16. Keeping to this blog, Shapiro's main point is shot down here
    http://sandwalk.blogspot.com/2007/01/central-dogma-of-molecular-biology.html

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  17. Pterosaur,

    If you hint that you mean IDiots, rather than scientific stuff, then don't act surprised, you get the answer corresponding to such IDiocy. I don't teach evolution. But evolution has lots to do with anything in biology, and evolutionary concepts have to be understood for ... well, for anything biology, basically. It has been just a couple of times that I used some ID rhetoric to have my students getting some concepts right (they did read the real thing, no rephrasing on my part).

    As for Shapiro. I don't know if he is an IDiot. I have read a couple of articles where he uses the metaphor of computations in bacterial stuff. As a metaphor it works. If he goes all the way to IDiocy elsewhere, well, then he becomes an IDiot, and I have no patience for someone becoming stupid enough to follow a metaphor too far into the idea that there must be an "intelligent designer." Such a thing would not be a real "challenge to current evolution thinking," but mere stupidity.

    As for real "challenges to current evolution thinking," where it is truly science (like horizontal gene transfer and what that means in terms of how we think about the evolutionary paths followed by organisms). Those tend to play a central role in my courses. That you can't distinguish between science, metaphors, and IDiocy is your problem, not mine. I perfectly see the differences, and, apparently, my undergrad students are capable of noticing them too. Since you are not one of my students, it is just up to you if you want to understand those differences or continue stubbornly in your self-impossed blindness.

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  18. The other Jim posted:
    "Keeping to this blog, Shapiro's main point is shot down here
    http://sandwalk.blogspot.com/2007/01/central-dogma-of-molecular-biology.html".

    That is not correct.
    If you want to make that claim, you will need to support it - with references to specifically what Shapiro has said.

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  19. How about from the abstract of
    Ann. N.Y. Acad. Sci. 1178: 6–28 (2009).

    " The discoveries relate to interactivemultimolecular execution of cell processes, themodular organization of macromolecules and genomes, the hierarchical operation of cellular
    control regimes, and the realization that genetic change fundamentally results from
    DNA biochemistry. These discoveries contradict atomistic pre-DNA ideas of genome
    organization and violate the central dogma at multiple points."

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  20. Dr. Shapiro has stated a fact.

    "These discoveries contradict atomistic pre-DNA ideas of genome
    organization and violate the central dogma at multiple points."

    Here is what he said about those discoveries:

    "The discoveries relate to interactive multimolecular execution of cell processes, themodular organization of macromolecules and genomes, the hierarchical operation of cellular
    control regimes, and the realization that genetic change fundamentally results from
    DNA biochemistry."

    In what way has he said something incorrect?

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  21. In case anyone is interested in the actual reference, here it is.

    Shapiro, J.A. (2009) Revisiting the Central Dogma in the 21st Century. Ann. N.Y. Acad. Sci. 1178: 6–28.

    Revisiting the Central Dogma

    Given the actual definition of The Central Dogma of Molecular Biology it's a relatively trivial exercise to demonstrate that Shapiro is full of ...

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  22. Rather than argue, consider this summary from Shapiro:

    "Underlying the central dogma and
    conventional views of genome evolution was the idea that the genome is a stable structure that
    changes rarely and accidentally by chemical fluctuations or replication errors. This view
    has had to change with the realization that maintenance of genome stability is an active
    cellular function and the discovery of numerous dedicated biochemical systems for restructuring
    DNA molecules. Genetic change
    is almost always the result of cellular action on the genome. These natural processes are analogous to human genetic engineering, and their activity in genome evolution has been extensively documented."

    And Shapiro's and other's extensive work supports this.

    http://shapiro.bsd.uchicago.edu/Shapiro2009.AnnNYAcadSciMS.RevisitingCentral%20Dogma.pdf

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  23. Anon,

    Dr. Shapiro has stated a fact.

    "These discoveries contradict atomistic pre-DNA ideas of genome organization and violate the central dogma at multiple points."


    Well, several things wrong right there. Thus not a fact. Conflating "atomistic pre-DNA views of genome organization" with the central dogma. What does one have to do with the other?

    Here is what he said about those discoveries:

    "The discoveries relate to interactive multimolecular execution of cell processes,


    The multimolecular execution of cell processes has nothing to do with the central dogma, nor with an atomistic view of genome organization.

    the modular organization of macromolecules and genomes,

    There is no such thing. The metaphor for a modular organization has helped to understand sometimes, but it has also been in the way. However, this again has nothing to do with central dogmas, nor with atomistic views of genome organization.

    the hierarchical operation of cellular control regimes,

    Some cellular "control regimes" are hierarchical, some are not. This also has nothing to do with atomistic views of genome organization, nor with the central dogma.

    and the realization that genetic change fundamentally results from DNA biochemistry."

    This seems a lot like a tautology. Of course genetic change has to be fundamentally linked to DNA "biochemistry" if genes are formed of DNA, then genetic change has to be changes in the DNA, and it has to occur according to how DNA reacts/replicates/et-cetera, right?

    In what way has he said something incorrect?

    In putting "central dogma" next to "atomistic views of genome organization," and then putting there misconceived and misunderstood "discoveries" that have nothing to do with either.

    It might be that you are not reading Shapiro's stuff correctly, or that you are misquoting, though. I don't know.

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