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    A Scientific Approach To Science Education - Reducing Cognitive Load
    By Carl Wieman | March 23rd 2009 12:56 PM | 6 comments | Print | E-mail | Track Comments

    Continued from Part 2, A Scientific Approach to Science Education - Research On Learning

    On average, students have more novicelike beliefs after they have completed an introductory physics course than they had when they started; this was found for nearly every introductory course measured. More recently, my group started looking at beliefs about chemistry. If anything, the effect of taking an introductory college chemistry course is even worse than for taking physics.

    So we are faced with another puzzle about traditional science instruction. This instruction is explicitly built around teaching concepts and is being provided by instructors who, at least at the college level, are unquestionably experts in the subject. And yet their students are not learning concepts, and they are acquiring novice beliefs about the subject. How can this be?

    Cognitive scientists have spent a lot of time studying what constitutes expert competence in any discipline, and they have found a few basic components.

    The first is that experts have lots of factual knowledge about their subject, which is hardly a surprise. But in addition, experts have a mental organizational structure that facilitates the retrieval and effective application of their knowledge. Third, experts have an ability to monitor their own thinking (“metacognition”), at least in their discipline of expertise. They are able to ask themselves, “Do I understand this? How can I check my understanding?”

    A traditional science instructor concentrates on teaching factual knowledge, with the implicit assumption that expert-like ways of thinking about the subject come along for free or are already present. But that is not what cognitive science tells us.  It tells us instead that students need to develop these different ways of thinking by means of extended, focused mental effort.  Also, new ways of thinking are always built on the prior thinking of the individual, so if the educational process is to be successful, it is essential to take that prior thinking into account.

    This is basic biology. Everything that constitutes “understanding” science and “thinking scientifically” resides in the long-term memory, which is developed via the construction and assembly of component proteins. So a person who does not go through this extended mental construction process simply cannot achieve mastery of a subject. 

    When you understand what makes up expert competence and how it is developed, you can see how cognitive science accounts for the classroom results that I presented earlier. Students are not learning the scientific concepts that enable experts to organize and apply the information of the discipline, nor are they being helped to develop either the mental organizational structure that facilitates the retrieval and application of that knowledge or a capacity for metacognition. So it makes perfect sense that they are not learning to think like experts, even though they are passing science courses by memorizing facts and problem-solving recipes.

    Improved Teaching and Learning

    If we now return to the puzzle of my graduate students—why their first 17 years of education seemed so ineffective, while a few years of doing research turned graduate students into expert physicists—we see that the first part of the mystery is solved: Those traditional science courses did little to develop expert-like thinking about physics.

    But why is working in a research lab so different?

    A lot of educational and cognitive research can be reduced to this basic principle: People learn by creating their own understanding. But that does not mean they must or even can do it without assistance.  Effective teaching facilitates that creation by getting students engaged in thinking deeply about the subject at an appropriate level and then monitoring that thinking and guiding it to be more expert-like.

    When you put it in those terms, you realize that this is exactly what all my raduate students are doing 18 or 20 hours a day, seven days a week. (Or at least that is what they claim—the reality is a bit less.) They are focused intently on solving real physics problems, and I regularly probe how they’re thinking and give them guidance to make it more expert-like. After a few years in that environment they turn into experts, not because there is something magic in the air in the research lab but because they are engaged in exactly the cognitive processes that are required for developing expert competence.

    Once I realized this, I started to think how these ideas could be used to improve the teaching of undergraduate science. Of course it would be very effective to put every student into a research lab to work one-on-one with a faculty member rather than taking classes. While that would probably work very well and is not so different from my own education, obviously it is not practical as a widespread solution.

    So if the economic realities dictate that we have to use courses and classrooms, how can we use these ideas to improve classroom teaching?

    The key is to get these desirable cognitive activities, as revealed by research, into normal course activities.

    I am not alone in coming to this conclusion. There is a significant community of science-education researchers, particularly in physics, who are taking this approach to the development and testing of new pedagogical approaches. This is paying off in clear demonstrations of improved learning.  Indeed, some innovative pedagogical strategies are sufficiently mature that they are being routinely replicated by other instructors with similar results.

    So what are a few examples of these strategies, and how do they reflect our increasing understanding of cognition?

    Reducing Cognitive Load

    The first way in which one can use research on learning to create better classroom practices addresses the limited capacity of the short-term working memory. Anything one can do to reduce cognitive load improves learning. The effective teacher recognizes that giving the students material to master is the mental equivalent of giving them packages to carry.

    With only one package, they can make a lot of progress in a hurry. If they are loaded down with many, they stagger around, have a lot more trouble, and can’t get as far. And when they experience the mental equivalent of many packages dumped on them at once, they are squashed flat and can’t learn anything.

    So anything the teacher can do to reduce that cognitive load while presenting the material will help.  Some ways to do so are obvious, such as slowing down. Others include having a clear, logical, explicit organization to the class (including making connections between different ideas presented and connections to things the students already know), using figures where appropriate rather than relying only on verbal descriptions and minimizing the use of technical jargon. All these things reduce unnecessary cognitive demands and result in more learning.

    carl wieman cognitive loads
    Students with low, medium and high cognitive loads.

    We'll address beliefs,guided thinking and technology in Part 4.


    W. Adams et al. (2005), Proceedings of the 2004 Physics Education Research Conference, J. Marx, P, Heron, S. Franklin, eds., American Institute of Physics, Melville, NY, p. 45.

    R. Hake (1998), The American Journal of Physics. 66, 64.

    D. Hammer (1997), Cognition and Instruction. 15, 485.

    D. Hestenes, M. Wells, G. Swackhammer (1992), The Physics Teacher. 30, 141.

    Z. Hrepic, D. Zollman, N. Rebello. “Comparing students’and experts’ understanding of the content of a lecture,” to be published in Journal of Science Education and Technology. A pre-print is available at http://web.phys.ksu.edu/papers/2006/Hrepic_comparing.pdf

    E. Mazur (1997), Peer Instructions: A User’s Manual, Prentice Hall, Upper Saddle River, NJ.

    G. Novak, E. Patterson, A.Gavrin, and W. Christian (1999), Just-in-Time Teaching: Blending Active Learning with Web Technology, Prentice Hall, Upper Saddle River, NJ.

    K. Perkins et al. (2005), Proceedings of the 2004 Physics Education Research Conference, J. Marx, P. Heron, S. Franklin, eds., American Institute of Physics, Melville, NY, p. 61.

    E. Redish (2003), Teaching Physics with the Physics Suite, Wiley, Hoboken, NJ.


    Originally presented in Change magazine, September/October 2007.


    Carl: I am really enjoying these articles, thank you so much!

    Your 'load' metaphor conjured up memories of me walking down school corridors carrying books, books and more books.  I never liked the time-slicing, one hour of this, one hour of that model.  Just when you think you are grasping a concept in math, somebody is shouting at you for not knowing what a thermodynamic cycle is in French.  I exaggerate.

    My love of learning, I owe directly to my parents.  If ever I asked my father "How does X work?" he would invariably reply: "How do you think it works?"  He was an intuitive teacher.  Having had little schooling in his own childhood, this self-taught man taught me the basics about the theories of Darwin, Mendel and many others.  He taught me, not facts, but how to learn, and that is pure gold.
    Gerhard Adam
    I think that an absolutely requirement of teaching any topic is to realize that (1) you are telling a story that must have a beginning, middle, end and (2) you must provide the motivation to the student that provides a suggestion why they should care.

    Everyone recognizes that a work of fiction fails if the reader fails to understand or relate to the characters, while in this case, the "characters" are the "facts" or objectives that we're trying to achieve.  The student must become engaged and interested in how things turn out.  Without that it's about as exciting as reading the dictionary.

    As an instructor you must be able to answer the question about how did YOU come to understand the topic being presented and why do you think it's important enough to take up someone else's time with it?
    Mundus vult decipi
    Thank you for your articles. I am helping to post them on my science educators homepage in the university I am attending. I do have a question that maybe you can address in your next article:

    As mentioned in this article how the quickness of teaching is often determined by economic factors and standardized tests, how can one slow down enough to lessen the cognitive load that the students are experiencing? This is especially applicable a problem when we consider how many classes each student takes in addition to the one they share with you. (I use to teach math in a US secondary school, and it seemed to be the biggest problem I would encounter).

    It also may make you feel happy that at least in New Zealand, the limit of cognitive load is stressed in the courses one has to take.

    Thank you.

    This is interesting and important and begs another important question: outside academia, where can learn this type of critical/scientific thinking? I can't think of a single place.

    Science journalism plays a similar role to teachers in that they rely mostly (I said mostly!) on factual knowledge and either don't convey or greatly simplify the problem solving that goes into firstly asking a question and designing a way to test it.

    It's important because the only way to achieve a consensus on climate change or evolution is not by telling each other what to think but agreeing on ways we can test our theories and abiding by the outcomes. We can't tell people what to think but we can agree on how we should think.

    Hello there Carl.

    I'm following your articles, and I think where you are going, having seen your
    presentation on mitworld http://mitworld.mit.edu/video/560.
    I'm sending this message to congratulate you for your initiative on education
    and the rigorous approach you are taking on it, and also to suggest a reading
    that could indicate some ways of improving the general beliefs regarding science
    and scientific problem-solving.
    Seymour Papert's Mindstorms book and most of the philosophy that surrounds his
    work are, I believe, and excellent light on this
    epistemological problem.
    Hugs and keep up the good work

    The same principle is being used in e-learning technology to make sure students do not get cognitive overload . Asynchronous  learning allows the student to work at their own pace to prevent cognitive overload and with the design of the multimedia a back button and forward button is there and the student can access the program anytime and anyplace. 
    E-learning through multi-media for students is something schools need to get caught up on , the kids are doing their computer games at homes ,Ipods,cell phones and many types of social networking and technology already . 

    ·         one main multimedia principal, Clark&Mayer “based on cognitive theory evidence and research, we recommend that e-learning courses include words and graphics, rather than words alone” (p.56). All of these elements of media, parts we learn to integrate and how they work with one another. That is what the rules are for, empirical data, and researched through scientific methods. Rules to improve for future learning.   

    Personalization is to know your learners or your audience and segmenting can be used for several reasons, one is not to have cognitive overload. 

    Synchronous e-learning: is delivered by an instructor or instructor led online e-course.

    Synchronous Collaboration: learners and instructors are interacting via computer.  


     Clark, R. C., & Mayer, R. E. (2008). e-Learning and the Science of Instructions: Proven 

         Guidelines for Consumers and Designers of Multimedia Learning. San Francisco: Pfeiffer.