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New information requires prior basic information

Archived: Building Pyramids: A model of of knowledge representation

By Efrat Furst (PhD), Post-doc Fellow at the Learning Incubator, SEAS, Harvard University. Her  background is in cognitive-neuroscientific research and professional development for educators.

Archived from https://sites.google.com/view/efratfurst/pyramids

Every new piece of knowledge is learnt on the basis of already existing knowledge.
The principle that organizes the knowledge is ‘Making Meaning’, or the ability to integrate and use a new concept in the context of what we already know.
In this pyramid model, every brick is a ‘piece of knowledge’ and the correct placement, on top of previous layer represents ‘meaning’, the final structure requires both.
Every pyramid is also a brick in a higher-level pyramid.

To learn a new piece of information (orange triangles) effectively, it should be learned on the basis of existing prior knowledge (gray triangles). Without prior knowledge (top panel), the new information cannot be integrated meaningfully (create a structure), and would most likely not survive overtime.

Knowledge Building Pyramids 1

Shing Y & Brod G (2016) Effects of Prior Knowledge on Memory: Implications for Education, Mind Brain and Education.

see also BLOOM’S TAXONOMY—THAT PYRAMID IS A PROBLEM by Doug Lemov

Higher order learning abilities like critical thinking, and creativity are depended on the existence of broad and well-established domain-specific knowledge, in one or more areas. Without this base, new high-level information cannot be structured appropriately, and hence will not be useful and will not be retained (top panel). The wider and more varied the basis of prior knowledge is, the higher, more complex and more creative structures it can support (bottom panel).

Knowledge Building Pyramids 2

Willingham, D. T. (2007). Critical thinking. American Educator, 31(3), 8-19

When the same routine of information is rehearsed during a session, a fast and impressive improvement may be evident . The gain, however, may not last long, when it is largely dependent on the specific context (of time, place, content, method, specific sequence etc.). When context fades as time goes by, the same level of performance cannot be maintained (top panel).

Knowledge Building Pyramids 3

However, when the study or practice in done in effective ways that emphasize crating meaningful connections to prior knowledge (elaboration), and between the newly learned items, we are building a stable structure of knowledge that may survive the passage of time and the absence of the learning context (bottom panel).

Prof. Robert Bjork on the distinction between Learning and Performance.

Bjork, E. L., & Bjork, R. A. (2011). Making things hard on yourself, but in a good way

Often we want learning or practice to be fun for ourselves of for our students, in order to build a positive experience. But if we wish to build knowledge through this experience, we must make sure that something is actually being built. Effective learning should include explicit elements of connecting the new knowledge to prior knowledge in meaningful ways (bottom panel), rather than just playing around with the new concept (top panel). Effective learning maybe more effortful (in a good way) than fun, but the long term results is usually rewarding.

Knowledge Building Pyramids 4

Prof Robert Bjork on Desirable Difficulties

Some things can be learned independently: when the relevant prior knowledge is available and when the learner is able to make the required connections between the new information and the existing knowledge (top panel). But for learning some other things guidance is essential: to supply information, or to to select the relevant information. Often guidance is needed to establish the nature of the relationships between the new and the existing information: a concrete example or a clear explanation that would make the pieces “fall” into the right place. With the appropriate guidance (bottom panel) more can be learned.

Knowledge Building Pyramids 5

Clark, R., Kirschner, P. A., & Sweller, J. (2012). Putting students on the path to learning: The case for fully guided instruction.‏

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From neuroscience to the classroom

26th September 2018, by Efrat Furst

Can neuroscience add anything to our understanding of the classroom? And what should teachers make of it? Efrat Furst looks into how this lens might prove useful in the future.

https://researched.org.uk/from-neuroscience-to-the-classroom/

 

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Developing writing skills: Verb wheel

Verb wheel

This is a verb wheel inspired by Bloom’s taxonomy. Every level within the cognitive domain has actions and verbs that are specific to it. This chart illustrates the 6 levels, followed by the verbs that are associated with them. It then shows the different activities which students engage in, which is associated with that level.

By utilizing these verbs and activities, it allows educators to address questions in such a way that students “climb the staircase” of Bloom’s Taxonomy and can eventually be able to master the material.

Verb Wheel Based on Bloom's Taxonomy

Footnotes

TBA

Learning Standards

TBA

Thinking well requires knowing facts

On his blog, Rough Type, author Nicholas Carr writes:

Mind Thinking Thoughts

With lots of kids heading to school this week, an old question comes back to the fore: Can thinking be separated from knowing?

Many people, and not a few educators, believe that the answer is yes. Schools, they suggest, should focus on developing students’ “critical thinking skills” rather than on helping them beef up their memories with facts and other knowledge about the world. With the Internet, they point out, facts are always within easy reach. Why bother to make the effort to cram stuff into your own long-term memory when there’s such a capacious store of external, or “transactive,” memory to draw on? A kid can google the facts she needs, plug them into those well-honed “critical thinking skills,” and – voila! – brilliance ensues.

That sounds good, but it’s wrong. The idea that thinking and knowing can be separated is a fallacy, as the University of Virginia psychologist Daniel Willingham explains in his book Why Don’t Students Like School

This excerpt from Willingham’s book seems timely:

I defined thinking as combining information in new ways. The information can come from long-term memory — facts you’ve memorized — or from the environment. In today’s world, is there a reason to memorize anything? You can find any factual information you need in seconds via the Internet. Then too, things change so quickly that half of the information you commit to memory will be out of date in five years — or so the argument goes. Perhaps instead of learning facts, it’s better to practice critical thinking, to have students work at evaluating all that information available on the Internet, rather than trying to commit some small part of it to memory.

This argument is false. Data from the last thirty years lead to a conclusion that is not scientifically challengeable: thinking well requires knowing facts, and that’s true not simply because you need something to think about. The very processes that teachers care about most — critical thinking processes such as reasoning and problem solving — are intimately intertwined with factual knowledge that is in long-term memory (not just found in the environment).

It’s hard for many people to conceive of thinking processes as intertwined with knowledge. Most people believe that thinking processes are akin to those of a calculator. A calculator has available a set of procedures  (addition, multiplication, and so on) that can manipulate numbers, and those procedures can be applied to any set of numbers. The data (the numbers) and the operations that manipulate the data are separate. Thus, if you learn a new thinking operation (for example, how to critically analyze historical documents), it seems like that operation should be applicable to all historical documents, just as a fancier calculator that computes sines can do so for all numbers.

But the human mind does not work that way. When we learn to think critically about, say, the start of the Second World War, it does not mean that we can think critically about a chess game or about the current situation in the Middle East or even about the start of the American Revolutionary War. Critical thinking processes are tied to the background knowledge. The conclusion from this work in cognitive science is straightforward: we must ensure that students acquire background knowledge with practicing critical thinking skills.

Willingham goes on the explain that once a student has mastered a subject — once she’s become an expert — her mind will become fine-tuned to her field of expertise and she’ll be able to fluently combine transactive memory with biological memory.

But that takes years of study and practice. During the K – 12 years, developing a solid store of knowledge is essential to learning how to think. There’s still no substitute for a well-furnished mind.

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Bloom’s Taxonomy

Bloom’s taxonomy is a widely accepted model about how students learn, created in the 1950s by Benjamin Samuel Bloom, an American educational psychologist.

It is a set of hierarchical models used to classify educational learning objectives into levels of complexity and specificity. They cover learning objectives in cognitive, affective and sensory domains.

Bloom edited the first volume of the standard text, Taxonomy of Educational Objectives in 1956. A second edition arrived in 1964, and a revised version in 2001.

In the original version of the taxonomy, the cognitive domain is broken into six levels of objectives: Knowledge, Comprehension, Application, Analysis, Synthesis, Evaluation. In the 2001 revised edition of Bloom’s taxonomy, the levels are changed to: Remember, Understand, Apply, Analyze, Evaluate, and Create.

This above introduction was excerpted and adapted from Wikipedia by RK.
“Bloom’s taxonomy.” Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 27 Sep. 2018.

Bloom's Taxonomy

Despite Bloom’s intentions for this to be used in college and graduate schools, it is now frequently used in American kindergarten through high school curriculum learning objectives, assessments and activities. Bloom himself was skeptical of this.

Despite popular belief, the taxonomy had no scientific basis.  Richard Morshead (1965) pointed out on the publication of the second volume that the classification was not a properly constructed taxonomy: it lacked a systemic rationale of construction.

Morshead, Richard W. (1965). “On Taxonomy of educational objectives Handbook II: Affective domain”. Studies in Philosophy and Education. 4 (1)

This criticism was acknowledged in 2001 when a revision was made to create a taxonomy on more systematic lines. Nonetheless, there is skepticism that the hierarchy indicated is adequate.  Some teachers do see the three lowest levels as hierarchically ordered, but view the higher levels as parallel.

Bloom himself was aware that the distinction between categories in some ways is arbitrary.  Any task involving thinking entails multiple mental processes.

The most common criticism, perhaps most important to hear today, is that curriculum designers implicitly – and often explicitly – mistakenly dismiss the lowest levels of the pyramid as unworthy of teaching. Common Core skills-based curricular and professional development drill into teachers the idea that we shouldn’t be teaching students “facts”; rather, we should encourage students to ask questions and investigate, and learn the material, organically, for themselves.

What this doctrine misses is the fact that today’s knowledge in math, science history, etc., is literally the product of thousands of thinkers and writers, and millions of man-hours of thinking, research, and peer-review. Constructing a substantial knowledge of algebra could take a student 20 or 30 years – or they could be taught supposedly “lower level facts” about the rules of algebra.

As you read the modern day evaluations of Bloom’s taxonomy, below, note the consensus: The learning of lower level skills is necessary to enable the building of higher level skills. And New information requires prior basic information

Thinking well requires knowing facts

Psychologist Daniel Willingham explains in his book Why Don’t Students Like School:

[Modern teachers have been told that] perhaps instead of learning facts, it’s better to practice critical thinking, to have students work at evaluating all that information available on the Internet, rather than trying to commit some small part of it to memory.

This argument is false. Data from the last thirty years lead to a conclusion that is not scientifically challengeable: thinking well requires knowing facts, and that’s true not simply because you need something to think about. The very processes that teachers care about most — critical thinking processes such as reasoning and problem solving — are intimately intertwined with factual knowledge that is in long-term memory (not just found in the environment)…. Critical thinking processes are tied to the background knowledge. The conclusion from this work in cognitive science is straightforward: we must ensure that students acquire background knowledge with practicing critical thinking skills.

From “Why Don’t Students Like School.”

Bloom’s Taxonomy: A Deeper Learning Perspective

Education Week, by Ron Berger

The problem is that both versions present a false vision of learning. Learning is not a hierarchy or a linear process. This graphic gives the mistaken impression that these cognitive processes are discrete, that it’s possible to perform one of these skills separately from others. It also gives the mistaken impression that some of these skills are more difficult and more important than others. It can blind us to the integrated process that actually takes place in students’ minds as they learn.

My critique of this framework is not intended to blame anyone. I don’t assume that Benjamin Bloom and his team, or the group who revised his pyramid, necessarily intended for us to see these skills as discrete or ranked in importance. I also know that thoughtful educators use this framework to excellent ends–to emphasize that curriculum and instruction must focus in a balanced way on the full range of skills, for all students from all backgrounds. But my experience suggests that what most of us take away from this pyramid is the idea that these skills are discrete and hierarchical. That misconception undermines our understanding of teaching and learning, and our work with students.

Here’s What’s Wrong With Bloom’s Taxonomy: A Deeper Learning Perspective, By Ron Berger, Chief Academic Officer at EL Education.

Bloom’s Taxonomy – That Pyramid is a Problem

by Doug Lemov

A couple of useful notes though. 1) Bloom’s is a ‘framework.’  This is to say it an idea—one that’s compelling in many ways perhaps but not based on data or cognitive science, say. In fact it was developed pretty much before there was such a thing as cognitive science. So it’s almost assuredly got some value to it and it’s almost assuredly gotten some things wrong. 2) I was surprised, happy and concerned (all at once) to read the italicized phrase: with the understanding that knowledge was the necessary precondition for putting these skills and abilities into practice.

Ironically this is exactly the opposite of what people interpret Bloom’s to be saying. Generally when teachers talk about “Bloom’s taxonomy,” they talk with disdain about “lower level” questions.  They believe, perhaps because of the pyramid image which puts knowledge at the bottom, that knowledge-based questions, especially via recall and retrieval practice, are the least productive thing they could be doing in class.  No one wants to be the rube at the bottom of the pyramid.

But this, interestingly is not what Bloom’s argued—at least according to Vanderbilt’s description. Saying knowledge questions are low value and that knowledge is the necessary precondition for deep thinking are very different things. More importantly believing that knowledge questions—even mere recall of facts—are low value doesn’t jibe with the overwhelming consensus of cognitive science, summarized here by Daniel Willingham, who writes,

Data from the last thirty years lead to a conclusion that is not scientifically challengeable: thinking well requires knowing facts, and that’s true not simply because you need something to think about. The very processes that teachers care about most — critical thinking processes such as reasoning and problem solving — are intimately intertwined with factual knowledge that is in long-term memory (not just found in the environment)

In other words there are two parts to the equation.  You not only have to teach a lot of facts to allow students to think deeply but you have to reinforce knowledge enough to install it in long-term memory or you can’t do any of the activities at the top of the pyramid. Or more precisely you can do them but they are going to be all but worthless. Knowledge reinforced by recall and retrieval practice, is the precondition.

Bloom's Taxonomy revised delivery

In the spirit of the FDA which recently revised its omnipresent food pyramid to address misconceptions caused by the diagram created to represent it, I’m going to propose a revision to the Bloom ‘pyramid’ so the graphic is far more representative. I’m calling it Bloom’s Delivery Service. In it, knowledge is not at the bottom of a pyramid but is the fuel that allows the engine of thinking to run. If I had more time for graphic design, I might even turn the pyramid on its side. You probably want to do quite a bit of analysis and synthesis but only if you’ve got comprehension solidly in the bag. In other words you kind of need all of the pieces.

– Doug Lemov

Teachlikeachampion.com/blog/blooms-taxonomy-pyramid-problem/

A Critical Appraisal of Bloom’s Taxonomy

Seyyed Mohammad Ali Soozandehfar and Mohammad Reza Adeli

American Research Journal of English and Literature (ARJEL), Volume 2, 2016

… In 1999, Dr. Lorin Anderson, a former student of Bloom’s, and his colleagues published an updated version of Bloom’s Taxonomy that takes into account a broader range of factors that have an impact on teaching and learning. This revised taxonomy attempts to correct some of the problems with the original taxonomy. Unlike the 1956 version, the revised taxonomy differentiates between “knowing what,” the content of thinking, and
“knowing how,” the procedures used in solving problems.

… Today’s world is a different place, however, than the one Bloom’s Taxonomy reflected in 1956. Educators have learned a great deal more about how students learn and teachers teach and now recognize that teaching and learning encompasses more than just thinking. It also involves the feelings and beliefs of students and teachers as well as the social and cultural environment of the classroom.

Anderson (2000) argues that nearly all complex learning activities require the use of several different cognitive skills. Like any theoretical model, Bloom’s Taxonomy has its strengths and weaknesses. Its greatest strength is that it has taken the very important topic of thinking and placed a structure around it that is usable by practitioners. Those teachers who keep a list of question prompts relating to the various levels of Bloom’s Taxonomy undoubtedly do a better job of encouraging higher-order thinking in their students than those who have no such tool.

On the other hand, as anyone who has worked with a group of educators to classify a group of questions and learning activities according to the Taxonomy can attest, there is little consensus about what seemingly self-evident terms like “analysis,” or “evaluation” mean. In addition, so many worthwhile activities, such as authentic problems and projects, cannot be mapped to the Taxonomy, and trying to do that would diminish their potential as learning opportunities. In the following sections, this study presents several in-depth criticisms:

…. it has been maintained that Bloom’s Taxonomy is more often than not interpreted incorrectly. Booker (2007) believes that “Bloom’s Taxonomy has been used to devalue basic skills education and has promoted “higher order thinking” at its expense” (2007, p.248). In other words, lower order skills such as knowledge and comprehension are being considered as less critical or invaluable skills.

Being referred to as lower order skills does not make knowledge or comprehension any less important, rather they are arguably the most important cognitive skills because knowledge of and comprehension of a subject is vital in advancing up the levels of the taxonomy. Therefore, in line with Booker’s conclusion, the Taxonomy is being improperly used. Bloom never stated that any of his cognitive levels were less important, just that they followed a hierarchical structure. Booker (2007) points out that even Bloom himself recognized that the application of the taxonomy was unexpectedly happening at the K-12 level and much less so at the university/college level.

The Misdirection of American Education

A Roof without Walls: Benjamin Bloom’s Taxonomy and the Misdirection of American Education, By Michael Booker

Abstract: Plato wrote that higher order thinking could not start until the student had mastered conventional wisdom. The American educational establishment has turned Plato on his head with the help of a dubious approach to teaching developed by one Benjamin Bloom. Bloom’s taxonomy was intended for higher education, but its misappropriation has resulted in a serious distortion of the purpose of the K–12 years. Michael Booker attributes the inability of American children to compete internationally to a great extent to our reliance on Bloom in expecting critical and advanced thinking from kids who have been trained to regard facts and substantive knowledge as unimportant.

Bloom’s Taxonomy has become influential to the point of dogma in American Colleges of Education.

Bloom’s Taxonomy has been used to devalue basic skills education and haspromoted “higher order thinking”at its expense.

Shortchanging basic skills education has resulted in producing students who misunderstand true higher-order thinking and who are not equipped for advanced education.

…. Soon after it was published, a body of research began to build around theTaxonomy. In 1970, Cox and Wildemann collected an index of the existing research into Bloom’s Taxonomy.12According to their study, 118 research projects of various sorts had been conducted in the previous decade and a half. A review of their data, however, shows that most of the research lacked experimental results that might either confirm or invalidate it. The results noted are not reassuring. Initial studies showed that individuals skilled in the Taxonomy frequently could not agree on the classification of test items or objectives.

… This adds up to an extraordinary misreading of the Taxonomy. Standards intended for college students get pushed down to the K–12 system. Instead of teaching those K–12 students hierarchically, the foundation of the structure is ignored. The push is made to the highest levels of the Taxonomy, especially level six, Evaluation. Since Handbook 1 is currently out of print (a measure, perhaps, of how carefully it is studied in the colleges of education), I will quote its caveats about Evaluation.

For the most part, the evaluations customarily made by an individual are quick decisions not preceded by very careful consideration of the various aspects of the object, idea or activity being judged. These might be termed opinions rather than judgments.…For purposes of classification, only those evaluations which are or can be made with distinct criteria in mind are considered.

Despite these warnings, typical Evaluation questions take the form of “What do you think about x?”and “Do you agree with x?” These questions are often accompanied by praise for what education literature misidentifies as the “SocraticMethod.” The result of this strategy is to occupy class time with vacuous opining.

When I speak with my fellow community college instructors, we rarely complain about student ’lack of advanced intellectual skills. Our chief source of frustration is that they haven’t mastered the basics needed to succeed in college-level work. Since I teach philosophy, I don’t expect my students to come to class knowing any content about my subject area.

Still, it would be lovely if they exited high school with some knowledge of world history, science, English, and geography. A large cohort (much to my frustration) doesn’t know how many grams are in a kilogram or when to use an apostrophe. I have a friend, Dr. Lawrence Barker, who once taught statistics at a state university. Each quarter he quizzed his incoming statistics students about basic math. The majority, he learned, couldn’t determine the square root of one without access to a calculator. He left teaching and is now happily employed by theCenters for Disease Control.

A Roof without Walls: Benjamin Bloom’s Taxonomy and the Misdirection of American Education, Michael Booker, Academic Questions 20(4):347-355 · December 2007

 

Alternative models of learning

Rex Heer, at the Iowa State University Center for Excellence in Learning and Teaching created this model. He writes:

Among other modifications, Anderson and Krathwohl’s (2001) revision of the original Bloom’s taxonomy (Bloom & Krathwohl, 1956) redefines the cognitive domain as the intersection of the Cognitive Process Dimension and the Knowledge Dimension. This document offers a three-dimensional representation of the revised taxonomy of the cognitive domain. Although the Cognitive Process and Knowledge dimensions are represented as hierarchical steps, the distinctions between categories are not always clear-cut. For example, all procedural knowledge is not necessarily more abstract than all conceptual knowledge; and an objective that involves analyzing or evaluating may require thinking skills that are no less complex than one that involves creating. It is generally understood, nonetheless, that lower order thinking skills are subsumed by, and provide the foundation for higher order thinking skills.

A Model of Learning Objectives by Rex Heer

The Knowledge Dimension classifies four types of knowledge that learners may be expected to acquire or construct— ranging from concrete to abstract.

Knowedge Dimension based on Bloom's

The Cognitive Process Dimension represents a continuum of increasing cognitive complexity—from lower order thinking skills to higher order thinking skills. Anderson and Krathwohl (2001) identify nineteen specific cognitive processes that further
clarify the scope of the six categories.

Cognitive Processes dimension based on Bloom's

Based on this, Rex Heer develops this three dimensional model. Again, please note that – as Bloom himself always intended – remembering facts (misunderstood as the “lowest” part of the method) – is actually the most important part: remembering facts is the base on which everything else depends. One can’t engage in higher level critical thinking skills on a subject without first knowing the content of the subject.

Rex Heer Revised Bloom's taxonomy

Model by Rex Heer, Iowa State University, Center for Excellence in Learning and Teaching, Jan 2012. Creative Commons Attribution Non Commercial-ShareAlike 3.0 Unported License.

http://www.vccs.edu/wp-content/uploads/2016/11/fyafi16-catherine-glaiser-course-design.pdf

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Why Old Physics Still Matters

By Chad Orzel, Forbes, 7/30/18

(The following is an approximation of what I will say in my invited talk at the 2018 Summer Meeting of the American Association of Physics Teachers. They encourage sharing of slides from the talks, but my slides for this talk are done in what I think of as a TED style, with minimal text, meaning that they’re not too comprehensible by themselves. So, I thought I would turn the talk into a blog post, too, maximizing the ratio of birds to stones…

(The full title of the talk is Why “Old Physics” Still Matters: History as an Aid to Understanding, and the abstract I sent in is:

A common complaint about physics curricula is that too much emphasis is given to “old physics,” phenomena that have been understood for decades, and that curricula should spend less time on the history of physics in order to emphasize topics of more current interest. Drawing on experience both in the classroom and in writing books for a general audience, I will argue that discussing the historical development of the subject is an asset rather than an impediment. Historical presentation is particularly useful in the context of quantum mechanics and relativity, where it helps to ground the more exotic and counter-intuitive aspects of those theories in a concrete process of observation and discovery.


The title of this talk refers to a very common complaint made about the teaching of physics, namely that we spend way too much time on “old physics,” and never get to anything truly modern. This is perhaps best encapsulated by Henry Reich of MinutePhysics, who made a video open letter to Barack Obama after his re-election noting that the most modern topics on the AP Physics exam date from about 1905.

This is a reflection of the default physics curriculum, which generally starts college students off with a semester of introductory Newtonian physics, which was cutting-edge stuff in the 1600s. The next course in the usual sequence is introductory E&M, which was nailed down in the 1800’s, and shortly after that comes a course on “modern physics,” which describes work from the 1900s.

Within the usual “modern physics” course, the usual approach is also historical: we start out with the problem of blackbody radiation, solved by Max Planck in 1900, then move on to the photoelectric effect, explained by Albert Einstein in 1905, and then to Niels Bohr’s model of the hydrogen atom from 1913, and eventually matter waves and the Schrodinger equation, bringing us all the way up to the late 1920’s.

It’s almost become cliche to note that “modern physics” richly deserves to be in scare quotes. A typical historically-ordered curriculum never gets past 1950, and doesn’t deal with any of the stuff that is exciting about quantum physics today.

This is the root of the complaint about “old physics,” and it doesn’t necessarily have to be this way. There are approaches to the subject that are, well, more modern. John Townsend’s textbook for example, starts with the quantum physics of two-state systems, using electron spins as an example, and works things out from there. This is a textbook aimed at upper-level majors, but Leonard Susskind and Art Friedman’s Theoretical Minimum book uses essentially the same approach for a non-scientific audience. Looking at the table of contents of this, you can see that it deals with the currently hot topic of entanglement a few chapters before getting to particle-wave duality, flipping the historical order of stuff around, and getting to genuinely modern approaches earlier.

There’s a lot to like about these books that abandon the historical approach, but when I sat down and wrote my forthcoming general-audience book on quantum physics, I ended up taking the standard historical approach: if you look at the table of contents, you’ll see it starts with Planck’s blackbody model, then Einstein’s introduction of photons, then the Bohr model, and so on.

This is not a decision made from inertia or ignorance, but a deliberate choice, because I think the historical approach offers some big advantages not only in terms of making the specific physics content more understandable, but for boosting science more broadly. While there are good things to take away from the ahistorical approaches, they have to open with blatant assertions regarding the existence of spins. They’re presenting these as facts that simply have to be accepted as a starting point, and I think that not only loses some readers who will get hung up on that call, it goes a bit against the nature of science, as a process for generating knowledge, not a collection of facts.

This historical approach gets to the weird stuff, but grounds it in very concrete concerns. Planck didn’t start off by asserting the existence of quantized energy, he started with a very classical attack on a universal phenomenon, namely the spectrum of light emitted by a hot object. Only after he failed to explain the spectrum by classical means did he resort to the quantum, assigning a characteristic energy to light that depends on the frequency. At high frequencies, the heat energy available to produce light is less than one “quantum” of light, which cuts off the light emitted at those frequencies, rescuing the model from the “ultraviolet catastrophe” that afflicted classical approaches to the problem.

Planck used this quantum idea as a desperate trick, but Einstein picked it up and ran with us, arguing that the quantum hypothesis Planck resorted to from desperation could explain another phenomenon, the photoelectric effect. Einstein’s simple “heuristic” works brilliantly, and was what officially won him the Nobel Prize. Niels Bohr took these quantum ideas and applied them to atoms, making the first model that could begin to explain the absorption and emission of light by atoms, which used discrete energy states for electrons within atoms, and light with a characteristic energy proportional to the frequency. And quantum physics was off and running.

This history is useful because it grounds an exceptionally weird subject in concrete solutions to concrete problems. Nobody woke up one morning and asserted the existence of particles that behave like waves and vice versa. Instead, physicists were led to the idea, somewhat reluctantly but inevitably, by rigorously working out the implications of specific experiments. Going through the history makes the weird end result more plausible, and gives future physicists something to hold on to as they start on the journey for themselves.

This historical approach also has educational benefits when applied to the other great pillar of “modern physics” classes, namely Einstein’s theory of special relativity. This is another subject that is often introduced in very abstract ways– envisioning a universe filled with clocks and meter sticks and pondering the meaning of simultaneity, or considering the geometry of spacetime. Again, there are good things to take away from this– I learned some great stuff from Takeuchi’s Illustrated Guide to Relativity and Cox and Forshaw’s Why Does E=mc2?. But for a lot of students, the abstraction of this approach leads to them thinking “Why in hell are we talking about this nonsense?”

Some of those concerns can be addressed by a historical approach. The most standard way of doing this is to go back to the Michelson-Morley experiment, started while Einstein was in diapers, that proved that the speed of light was constant. But more than that, I think it’s useful to bring in some actual history– I’ve found it helpful to draw on Peer Galison’s argument in Einstein’s Clocks, Poincare’s Maps.

Galison notes that the abstract concerns about simultaneity that connect to relativity arise very directly from considering very concrete problems of timekeeping and telegraphy, used in surveying the planet to determine longitude, and establishing the modern system of time zones to straighten out the chaos that multiple incompatible local times created for railroads.

Poincare was deeply involved in work on longitude and timekeeping, and these practical issues led him to think very philosophically about the nature of time and simultaneity, several years before Einstein’s relativity. Einstein, too, was in an environment where practical timekeeping issues would’ve come up with some regularity, which naturally leads to similar thoughts. And it wasn’t only those two– Hendrik Lorentz and George FitzGerald worked out much of the necessary mathematics for relativity on their own.

So, adding some history to discussions of relativity helps both ground what is otherwise a very abstract process and also helps reinforce a broader understanding of science as a process. Relativity, seen through a historical perspective, is not merely the work of a lone genius who was bored by his job in the patent office, but the culmination of a process involving many people thinking about issues of practical importance.

Bringing in some history can also have benefits when discussing topics that are modern enough to be newsworthy. There’s a big argument going on at the moment about dark matter, with tempers running a little high. On the one hand, some physicists question whether it’s time to consider alternative explanations, while other observations bolster the theory.

Dark matter is a topic that might very well find its way into classroom discussions, and it’s worth introducing a bit of the history to explore this. Specifically, it’s good to go back to the initial observations of galaxy rotation curves. The spectral lines emitted by stars and hot gas are redshifted by the overall motion of the galaxy, but also bent into a sort of S-shape by the fact that stars on one side tend to be moving toward us due to the galaxy’s rotation, and stars on the other side tend to be moving away. The difference between these lets you find the velocity of rotation as a function of distance from the center of the galaxy, and this turns out to be higher than can be explained by the mass we can see and the normal behavior of gravity.

This work is worth introducing not only because these galaxy rotations are the crux of the matter for the current argument, but because they help make an important point about science in context. The initial evidence for something funny about these rotation curves came largely from work by Vera Rubin, who was a remarkable person. As a woman in a male-dominated field, she had to overcome many barriers along the course of her career.

Bringing up the history of dark matter observations is a natural means to discuss science in a broader social context, and the issues that Rubin faced and overcame, and how those resonate today. Talking about her work and history allows both a better grounding for the current dark matter fights, and also a chance to make clear that science takes place within and is affected by a larger societal context. That’s probably at least as important an issue to drive home as any particular aspect of the dark matter debate.

So, those are some examples of areas in which a historical approach to physics is actively helpful to students, not just a way to delay the teaching of more modern topics. By grounding abstract issues in concrete problems, making the collaborative and cumulative nature of science clear, and placing scientific discoveries in a broader social context, adding a bit of history to the classroom helps students get a better grasp on specific physics topics, and also on science as a whole.

About the author: Chad Orzel is Associate Professor in the Department of Physics and Astronomy at Union College

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How to teach AP physics

It’s easy to teach physics in a wordy and complicated way – but taking a concept and breaking it down into simple steps, and presenting ideas in a way that are easily comprehensible to the eager student, is more challenging.

Yet that is what Nobel prize winning physicist Richard Feynman excelled at.  The same skills that made one a good teacher also caused one to more fully understand the topic him/herself. This was Feynman’s basic method of learning.

Feynman How to teach physics

1) Develop an array of hands-on labs that allow one to study basic phenomenon.

You can also use many wonderful online simulations, such as PhET or Physics Aviary.

2) Each day go over several problems in class. They need to see a master teacher take what appears to be a complex word problem, and turn it into equations.

3.) Insure that students take good notes.  One way of doing this is having the occasional surprise graded notebook check (say, twice per month.)

4) Each week assign homework. Each day randomly call a few students to put one of their solutions on the board. Recall that the goal is not to get the correct numerical answer. (That sometime can come by luck or cheating.) Focus on the derivation. Does the student understand which basic principles are involved?

5) Keep track of strengths and weaknesses: Is there a weakness in algebra, trigonometry, or geometry?  When you see a pattern emerge, assign problem sets that require mastering the weak area – not to punish them, but to build skills. Start with a few very easy problems, and slowly build in complexity. Let them work in groups if you like.

6) Don’t drown yourself in paperwork: Don’t grade every problem, from every student, every day. You could easily work 24 hours a day and still have more work to do. Only collect & grade some percent of the homework.

7) Focus on simple drawings – or for classes that uses programming to simulate physics phenomenon – simple animations. Are the students capable of sketching free-body diagrams that strip away extraneous info? Can they diagram out all the forces on an object?

8) Give frequent assessments that are easy to grade.

9) Get books such as TIPERS for Physics, or Ranking Task Exercises in Physics. They are diagnostic tools to check for misconceptions.. Call publishers for free sample textbooks and resources. For a textbook I happen to like Giancoli Physics; their teacher solution manual is very well thought out.

Prof Devel log NGSS Science discussion group

Sample prof development log for teachers in a NGSS Science Facebook discussion group.

Prof Development Log for FB Science teachers group (MS Doc format)

Prof Development Log for FB Science teachers group, PDF format

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