Saturday, November 22, 2008
At the risk of repeating information that many readers may know about, I wanted to make quick post about the astrolrner listserve, the email discussion group for astronomy teachers, hosted by the Center for Astronomy Education. It is a moderated listserve (full disclosure: currently guest moderated by myself), so all messages are on-topic and members never receive spam or unrelated email by subscribing. Like most listserves, you can opt for individual emails and receive each post as they come in, or you can receive a daily digest of messages.
Astrolrner has over seven-hundred members, and it goes through flurries of activity every couple weeks or so. I have found it to be a valuable resource, because it allows me to see what other teachers are doing in their classrooms. Other members often request help with a particular assignment, generally finding that someone has developed a similar activity. The discussion can be quite lively, and, since it is moderated, they remain civil and on-topic.
If you are an astronomy teacher, then you should join astrolrner.
Erik Brogt and his collaborators have written a series of three articles in Astronomy Education Review that not only detail the research ethics of studying students, but also present guidelines for the astronomy education research community. I think any researcher studying student learning of astronomy can benefit from reading these articles, regardless of whether or not there is intent to publish.
Regulations and Ethical Considerations for Astronomy Education Research, from July 2007, provides an overview of human subject research. The article applies this overview to astro ed research.
Regulations and Ethical Considerations for Astronomy Education Research II: Resources and Worked Examples, from January 2008, details the processes of an Institutional Research Board (IRB), and gives ethics considerations for several example astro ed research studies.
Regulations and Ethical Considerations for Astronomy Education Research III: A Suggested Code of Ethics, from November 2008, completes the series, giving a proposed set of ethical guidelines that astronomy education researchers should follow.
The guidelines are not dissimilar from other fields, but since our field is relatively young, I think having them specifically listed provides a good example for future research.
Sunday, August 3, 2008
This summer, I began work in the Master of Science in Science Education (MSSE) program at Montana State University. Two of my on-campus summer courses were out of the Physics by Inquiry curriculum. One course focused on electric circuits, and the other focused on light, color, and geometric optics. Even with my background in physics and astronomy, I learned a great deal of physics in these courses.
Physics by Inquiry (PbI) is the product of decades of research by Lillian McDermott and the Physics Education Group (PEG) at the University of Washington. The curriculum is completely learner-centered, in that there is essentially no lecturing at all. Students work in collaborative groups on observations, experiments and exercises. The activities were designed to help students confront common misconceptions and see that other, more accurate explanations are needed. The activities lead the students to develop accurate and mature scientific models of the phenomenon being studied. For example, in my four-week course, I think I learned more about basic circuits than I did with the more abstract and mathematical approach I had as an undergraduate physics major. The circuits module breaks the topic into two models: current and voltage. By the end of the module, students have two models they can use to analyze any basic situation with circuits (pre-RC circuits).
By the end of the two courses, I had become enamored of the curriculum. I started to wonder why all introductory physics courses aren't using it. The answer, without getting into other, more historical and political, reasons, is logistics. McDermott and the PEG recommend a student-to-teacher ratio of 7:1, so a course with 200 students becomes too unwieldy even for a teacher with two or three TAs. My own courses have no more than 36 students in them, and I would still need a TA or two to help answer student questions and check on groups so that incorrect models and misconceptions don't form.
PbI has two astronomy modules. Astronomy by Sight: The Sun, Moon, and Stars builds models for the path of the Sun (Daily motion, with some seasonal change), phases of the Moon, and daily motion of the stars. Astronomy by Sight: The Earth and Solar System leads into yearly variation of the Sun and stars on the celestial sphere. What I love about the modules is that they are completely based on long-term observations that students make themselves.
Because of the long-term nature of the modules, and the fact that I have no teaching assistants, there is no easy way for me to implement the astronomy curriculum in the lecture sections of my Astro 101 courses. However, my Astro 101 course has a weekly lab associated with it. Because the labs are significantly smaller than the lecture sections, the students/teacher ratio is improved. Lab would be an appropriate venue for the inquiry approach. This fall, I think I am going to experiment with the modules and see how they work with my community college students. My suspicion is that the activities will blend well into the course. With this radical departure from my traditional lab format, I will also change the order of topics in my lectures. Historically, I had always started with naked-eye astronomy, with students doing the lecture tutorials on the celestial sphere first in the semester. With the inquiry modules being worked in lab, I think it will be beneficial to move the celestial sphere discussion to last in the semester, so that students approach the abstract tutorials with models they have built themselves over the course of many weeks.
If any Teaching Astronomy readers have experience with the PbI astronomy modules, please comment here with your insights.
Westchester Community College
Tuesday, June 10, 2008
The question of if and which textbook often comes up among astronomy teachers and the opinions range pretty widely – when opinions range widely, I love to get into the frey, so here goes my $0.02.
Most folks who have moved away from textbooks entirely face a pretty serious problem in that the professor and the professor’s notes become the sole source of knowledge and expertise in the class. Sure students CAN go look up stuff and get another perspective, but my sense is that they don’t. So, the result is an implicit and sizeable pressure for students to memorize what professors say (or type) and that is what they are able to answer on exams: professors feel a sizeable pressure to only ask questions about what they specifically talk about in class. For my money, this is a lose – lose bet. Seems to me that the professor’s job should be about linking students’ thinking to the ideas of astronomy, not about delivering the ideas in their entirety.
Some folks have tried using trade books or coffee table books or extensive fact-based web sites. Although these are attractive, particularly in how they are illustrated, they lack the tried-and-true pedagogical tools that many, many students, publishers, and authors have worked through and tried to perfect over the years – explicitly stated learning goals, headings to structure student thinking, end of chapter summaries with review questions, and, gasp, even bold faced words to help focus student attention. I’m not saying that these things are perfect and are not often overused, BUT, what I would say is that these pedagogical clues are important enough to student readers that having them in a textbook is more important than the pretty pictures and pedagogy-less writing of coffee table books.
So, for my money, I think using a textbook is an important part of the introductory science survey course. Yes, they are expensive, but in the grand scheme of things that go into a college education, they really aren’t. My most convincing evidence is that the $35 that students pay for the Lecture-Tutorials seems outrageous for a “works book” BUT, students rarely complain because they really, really use the book as part of their learning and they find it valuable. If students felt that the astronomy textbook helped them learn the material and they found it valuable, they wouldn’t care if it cost $200 (of course, if you haven’t looked at the half priced e-books for students as an option, you should – they are getting really good!). I think the problem that most astronomy faculty face related to textbooks is simply OPERATOR ERROR. If professors never ask students to be responsible for learning from the textbook without the instructor repeating or, even worse, and I’ve seen it, reading from the textbook during lecture, then why would students ever think a textbook is valuable. This problem is much more well documented in physics than astronomy, where many physics professors don’t’ use the textbook for anything other than problems at the end of the chapter. Eric Mazur says that, even at Harvard, students won’t read unless you require it of them. I think this applies no matter what your student demographic is (I say this for those who are about to say, “but my community college students couldn’t possibly read the book” – I don’t see any truly convincing evidence of this – readability on astronomy books show that many are at pre-high school level nowadays)
Now, my opinion is that students should be required to learn from the textbook and that portions of exams should be allocated to material from the textbook that is NOT covered in lecture. I don’t want to spend my valuable class time telling them facts they can read in a much more precise and attractive language than I can “say” during class time.
I will take this opportunity of a bully pulpit to comment on students using Wikipedia (since you’ve read this far). Numerous studies have been done on the likes of Wikipedia which almost always come to the same conclusion--the community checking nature of it results in a higher accuracy rate than even the most traditionally respected of resources, such as Encyclopedia Britannica or even your astronomy textbook. Therefore, I’m perfectly comfortable allowing students to use Wikipedia as a resource – the research clearly shows that it is as accurate as their textbook, if not more so. However, I recognize that some faculty are loathe to allow students to use Wikipedia, partially because they hate to deal with the click copy paste approach many students use and partially because it seems too convenient and students should have to go to the library to do research. (Of course, I’m trying to remember the last time I had to leave my computer to go to the library to look up something – them days are over methinks.) I am more inclined to give students creative writing assignments that click-copy-paste won’t work for.
Enjoying Laramie, Tim
Tim Slater, University of Wyoming Excellence in Higher Education Endowed Professor of Science Education, firstname.lastname@example.org
Thursday, May 8, 2008
2000 Florida Avenue, NWSuite 400
Washington, DC 20009
Email Submission Address: email@example.com
(subject line: AER Editor Search)
Applications will be reviewed starting June 15 and will continue until position is filled.
Attention: Tim Slater, Chair, AER Editor Search Committee
The American Astronomical Society is soliciting applications and nominations of candidates for the position of Editor of the Astronomy Education Review (AER). This person will replace the current Editor, Sidney Wolff, who is stepping down at the end of 2008. The AER is internationally known as the pre-eminent scholarly journal in astronomy education and research, and the new Editor will be responsible for enhancing the excellence of the Journal. The AAS Council has selected a Search Committee to fill this position, chaired by its Education Officer, Tim Slater.
The Search Committee has identified the following qualifications that must be satisfied by the successful applicant:
1. Recognized stature and achievement in astronomy and/or science education.
2. Experience with diplomatic management of peers, staff, or students.
3. A clear vision for the future of the AER.
4. Familiarity with budgets.
5. Experience as a referee.
6. Previous editorial experience would be useful but is not required.
The Editor is responsible for building and maintaining a cadre of referees and assigns most manuscripts submitted to the referees, assesses the referee's reports and recommends the papers for publication. The Editor is responsible for maintaining the efficient and timely flow of manuscripts.
As part of this process, this person will also:
1. Actively recruit authors and referees.
2. Interface with the AAS Journals Manager.
3. Participate in the establishment and management of the Journal Budget.
4. Report to the Publications Board and the AAS Council on the status of the AER.
The Society expects to compensate the Editor at roughly $10,000 per year paid as a stipend (or other arrangements as negotiated) and performance will be reviewed annually by the publications board. No additional infrastructure will be provided. Specific questions about the historical operations of the journal to date can be addressed to Sidney Wolff, firstname.lastname@example.org .
Candidates for this position should submit a cover letter, CV, bibliography, and names and contact information of three references to Tim Slater, Chair of the AER Editor Search Committee, at the above address. Email submission of PDF files is encouraged to email@example.com using AER Editor Search as subject line.
Nominations for the position may also be sent to the same address.
Selected candidates will be asked to provide evidence of institutional support for their assuming the above editorial duties.
The cover letter should address the candidate's qualifications, reason for interest in the position, and ideas for the operation, management, and future of the AER. In accordance with the Bylaws of the Society,the Search Committee will make its recommendations to the AAS Publications Board and AAS Council. The final selection is made by the Council. Applications and nominations received by 15 June 2008 will be givenfull consideration. AAE/EOE.
The current website of the Astronomy Education Review is http://aer.noao.edu/.
Friday, April 25, 2008
Around this time of the semester, I am covering galaxies, large-scale structure, and cosmology. The other day, the folks at the HST released a wonderful webpage filled with the best Hubble images of galaxy collisions I have ever seen. Scroll to the bottom of that page to see links to the individual images.
Showing pretty pictures in class is one way to interest students. When it comes to colliding galaxies, you don't have to just show the static pictures though. Some astronomers at CWRU and the University of Oregon have developed a web-based applet, called GalCrash, that simulates the dynamics of colliding galaxies. You can choose many different parameters for the simulation, including number of stars and mass, etc.
What I like about this applet is that you can run a simulation and achieve a result that is similar to the morphology shown in the actual images of galaxy collisions. Just pause the applet and show the comparison to students! I think it's a neat way to connect physical theory with observations.
Saturday, April 5, 2008
The first time I attended a Center for Astronomy Education (CAE) Teaching Excellence workshop was also the first time I had really seen the technique of peer instruction. By "peer instruction", I mean the kind promoted by Eric Mazur: A class discusses a topic, or receives a short lecture, and then a series of multiple choice questions are posed. The results of the voting influences how the teacher will give instruction.
But how to vote? Certainly anonymous voting is nice, taking pressure off the students who are nervous or shy about revealing their answers in front of everybody. One way of voting is to use your hands: vote with your fingers. Multiple choice answer "A" is one finger; "B" is two fingers, and so on. Placing your vote on your chest prevents the students behind you from seeing your vote.
Another way to vote is using flash cards. In this way, colored flash cards printed with a letter on them are held up to indicate a vote.
In my own classroom, I use multiple choice questions a lot, and my students vote with their fingers.
In the last fifteen years or so, electronic devices have been introduced into the voting classroom. "Clickers" are remote devices that resemble tv remotes that can transmit a student's answer to the professor's computer.
Also in my first CAE workshop, I recall Ed Prather voicing skepticism as to whether or not it mattered if a student used flash cards or a clicker. Certainly, there is evidence that students are excited about using the technology, but does the use of clickers in voting change the pedagogical landscape? Or is it just as good to use flash cards (or fingers)?
Some new data has come in. Nathaniel Lasry of John Abbott College has an article in this month's Physics Teacher entitled Clickers or Flashcards: Is There Really a Difference?. I'll let you read the article, but Lasry's main conclusion is that there is no pedagogical difference between the two tools, provided that the same method of peer instruction is given. This makes sense to me, since there doesn't seem to be a way cognitive load would change between using a clicker or using a flash card.
The main advantage of using clickers is the electronic culling of voting data. Some clicker systems are so advanced that they can collect the data, analyze it and generate webpages in which you can view class and individual student performances across class sessions and entire semesters. Voting with your fingers doesn't allow this.
One thing seems clear from this: lack of technology should not stop you from introducing peer instruction into your classroom.
Friday, March 28, 2008
Science is not a dogma. It is a process.
A major responsibility we have in teaching any introductory science course, including astronomy, is to discuss how the scientific process works and the differences between science and pseudoscience. In the curriculum I have put together for my Astro 101 course, I include a few days on these topics (I should really have more!). In class, we discuss Occam’s Razor, falsification, peer review, pseudoscience, and logical fallacies, just to name a few topics. A major issue that I feel is important to bring up is that science has built in agnosticism. The idea that there is an invisible, omnipresent and omniscient God (or gods) that created the Universe and the life within it is an un-falsifiable hypothesis. There are no observations that we can make of the Universe before time zero. If anything was happening before the Universe started, we will probably never know about it. Any predictions made about what was happening before the Universe, whether they are the colliding branes of string theory, or the machinations of deities, are un-testable and so cannot be verified by science. Science must be agnostic when it comes to the origins of the Universe.
Science is also apolitical. It is merely a process by which we can discover ever more useful models that explain the workings of nature. The results of these models do not tell us whether we should join a Kyoto Protocol, they only give a range of possible outcomes. The results of scientific models have never said outright that the manufacturing industry should be regulated. The results only give detected levels of heavy metals in soils and water sources. Science has nothing to say about what people and politicians should do. It only provides data and models that can possibly be used in making pragmatic decisions.
Teaching science in the science classroom
An introductory science classroom should be about learning the results and processes of modern mainstream science. If I went to my curriculum committee and said that my school should teach Newton’s Laws in the World Religions course, I would be laughed at. But this is the kind of scenario we are witnessing across the country. Politically and religiously motivated people have decided that the results and processes of modern science are incongruous with their deeply held beliefs. They petition local school boards to adopt new definitions of science that inject supernatural causes into models of nature. They ask that equal time be given to other explanations (well, just one actually) of the Universes origins. They ask that if evolution is taught, then students should be subjected to a laundry list of (logically and scientifically unsound) “problems” with evolution.
The people who oppose the results and processes of modern science know that creationism and Intelligent Design will not gain a foothold within the scientific community. The reason is simple: these explanations make ZERO useful predictions that can be verified through observation and experiment. I have been careful to place the word “useful” in the last sentence. Certainly predictions can be made from following the reasoning of creationism. If the Biblical story of creation is to be taken literally, then we should occasionally find human fossils (or even horses, etc) among the ancient strata that actually do contain fossils of less developed organisms. In all of paleontology, no such observation has been made. Does this mean that it will not be made? No, but the likelihood is so small as to make the search for a human fossil there a waste of time. The best creationism and Intelligent Design can do is to generate philosophical and scientifically illiterate objections to evolution. Merely making objections does not qualify a set of ideas as a modern science.
Because of the failure of creationism and Intelligent Design to make any useful predictions about nature, there are very few peer-reviewed journal articles published that promote these ideas. Creationism and Intelligent Design are not likely to contribute any new and exciting ideas to modern science. Any scientific model of nature that wishes to become the dominant explanation of biology needs to be at least as useful as the current model. The current model is evolution. Modern biological evolution is useful and makes many novel predictions and retrodictions. However, contrary to what the anti-evolutionists say, biological evolution has nothing to say about what caused life to appear on the Earth in the first place.
Creationism and Intelligent Design have failed to gain traction within the scientific community because they are useless ideas. So, proponents of these ideas go to the courts and the school boards. It does not appear difficult to convince a school board to adopt educational standards that include the teaching of creationism and intelligent design in science classrooms. It does, however, appear difficult to get a court to agree on that point (just look at the Dover, PA court case on Intelligent Design).
ID proponents claim that scientists are part of a conspiracy
A new tactic has become the norm within the creationist and Intelligent Design community. It is a psychological tactic, meant to prey on the sense of fairness that Americans largely have. ID proponents now claim that mainstream science is suppressing their research and actively engaged in keeping ID out of the classroom. If ID is being kept out of the science classroom, it is because of the reasons I outlined above. It is not a useful model of nature and has no foreseeable promise as a part of modern science. But that is not what ID proponents are giving as the reason their ideas are rejected. They say that mainstream science is filled with “materialism”, a emotionally-loaded and nebulous term which asserts that scientists deny God and any sort of spirituality.
It is true that an individual scientist may be an atheist. But if they have that position, it is not because the process of science dictates it. Remember, science is agnostic. When ID proponents call mainstream scientists “materialists”, they are poisoning the well of public opinion. A scientist may just as well be a Christian or a Buddhist or an atheist. Such a position does not matter in the overall scope of the scientific process. But, of course, this is not the message ID proponents want people to know about.
To disseminate the message that scientists are close-minded “materialists”, ID proponents, mainly funded by the Discovery Institute (the major pro-ID organization), have produced a film called Expelled (subtitle: “No Intelligence Allowed”). It appears to be a documentary containing interviews by the mildly-recognizable Ben Stein. The ads for the film have taglines that say “Big Science has expelled smart new ideas from the classroom”. Did you see what they did? “Big Science”. It sounds like “Big Tobacco” or “Big Oil”.
Reports are in from those who have seen the advance prints of the film. Expelled tries to equate evolution with eugenics, implying that evolution was the cause of the Holocaust. The producers filmed interviews with prominent evolutionary scientists, such as Richard Dawkins and PZ Meyers. The interviews were under false pretenses. Dawkins and Meyers were told that the film was called “Crossroads” and that it was about science and religion. They were not told it was an Intelligent Design propaganda piece.
To Ben Stein, and creationism and ID proponents, I say this: “If you want to teach ID in the classroom, that is fine with me. Now, what is the specific, useful, and testable model that you will you teach?” This simple question should be enough to give pause to anybody who thinks scientists are trying to “expel” ID from the classroom.
This issue matters to all science teachers
So why am I writing about this in the Teaching Astronomy blog? Inevitably, when teaching about the nature of science and the difference between science and pseudoscience, you will have students ask you about this film (either in class or after class). It is best to know about these major salvos before you are told about them by students. You do not need to engage in a debate with students over religion, but you should have a stock of responses to the main points that the ID proponents are making today. You do not need to know how to respond to every claim that creationists make, but you should know where to direct students to find reliable information, such as the Index to Creationist Claims.
Introductory astronomy, earth science, astrobiology teachers must all discuss ideas that are controversial to the creationist set: the age of the Earth, age of the Universe, formation of stars and the creation of heavy elements, to name a few. I'm sure that we all understand the dangers of allowing creationism to enter the class through school boards and the courts. But now we must be aware of this new campaign based on emotional nudging. If a students says that science is "materialistic", remind your class about the agnostic nature of science. Science is not a dogma, it is merely a process.
Thursday, March 27, 2008
It seems like all the hard work should pay off, doesn’t it? You’ve been working feverishly on preparing your lecture notes to carefully cover all the many ideas for the topic. You’ve been madly searching Internet sites to find just the right image or animation to share with the audience that you hope will make complex ideas crystal clear. You’re allocating considerable time to organize as many of these resources as possible into projected PowerPoint presentations that can be shared electronically with listeners and maybe even building multi-layered www sites with countless hyperlinks to even more detailed information than you’ll have time to adequately describe during lecture.
One has to wonder if all of this is really worth it? Faculty often report that, for the first time they give a lecture, they allocate at least three to five hours for preparing. Then, during coffee and dinner conversations after the lecture, even the most knowledgeable, enthusiastic, and dedicated lecturers find that too often far too many people missed the big idea. All the bases are covered, and yet no one is fully satisfied in the end. How could this possibly be?
It is possible that as you read this, you are saying to yourself, “oh, no, not me, not my lectures. Everything is going great in my lectures.” Well, that might well be true as there are some amazing teachers out there who are doing amazing things during their lectures. However, it is my position that every lecture can be improved. Sometimes it can mistakenly appear that everything is going just fine, when it really isn’t. In too many lectures, students quietly tune out using a strategy that they can just “copy it down now and try to figure it out later.” This is because many professors and students have a sort of “hidden classroom contract” with one another. In brief, this hidden classroom contract implicitly states something to the effect of, “the professor will tell the students what to memorize and will only ask students questions directly related to this list on the exams and, in exchange, students will dutifully memorize the material given during lecture and, if students fail to adequately memorize the material, students will not complain too loudly if a poor grade is assigned.”
Rethinking Your Lectures to be Learner-Centered
The first step is to accept that much of the responsibility for learning resides squarely on the listener—not actually on the professor. Faculty can motivate, inspire, and build a series of experiences that make the discipline more accessible; but, faculty can not do the learning for them. In fact, this notion has encouraged us to adopt the perspective, “it’s not what the instructor does that matters; rather, it is what the students do.” But, there is still plenty for the lecturer to do!! The role of lecture in a learner-centered teaching perspective still exists, but is radically shifted from dispensing knowledge in a conventional course to a focus on guiding students through meaningful learning experiences as a learner-centered experience. So, the pathway to giving great lectures is to change listener behavior from passive to active! Here, allow me to suggest some interactive teaching strategies that have been shown to significantly increase the amount of student comprehension. These approaches do dramatically reduce the number of words you get to say as a lecturer; but with a little preplanning, it does not drastically reduce the amount of information you can cover. This works incredibly well and few people who have gone down this alternative road have ever gone back to their old ways.
The most valuable role of an expert is not to simply tell students what they know; rather, it is to use their unique expertise to build rich scenarios for students to analyze using novel ideas.
Faculty in the sciences have the distinct advantage over faculty in other disciplines in that demonstrations, whether physical or computer-based, can be provocative, provide illustrative clarification, and, most importantly, excite the learner through direct experiences with unexpected physical phenomena. However, the research on the actual effectiveness of demonstrations is clear. The most important part of the demonstration is asking students to predict what they will see—predictions committed to in writing—and for students to predict what will happen when particular variables are changed. It is the act of predicting and rationalizing these predictions where most of the learning occurs from demonstrations and simulations. So, stop, and take the time to ask “what do you think you’ll see?”
The central part of a learner-centered approach is to ask questions. To be sure, a pointed suggestion of asking students some questions during a lecture might seem a tad silly. However, the number of faculty who actually pose non-rhetorical questions is surprisingly small. Probably the biggest mistake that faculty make is to pose cognitively low-level questions that are too easily answered by students relying on preexisting declarative knowledge. Students responding quickly, and in unison, is often mistaken for meaningful dialogue between a professor and the class. Questions should be intellectually challenging and be carefully crafted to lead the students to deeper levels of understanding or to illustrate the power of scientific ideas. In a similar way, questions such as “does everyone understand?” and “do you have any questions?” do not provide faculty with the desired insight into whether or not students actually comprehend the ideas being presented.
Particularly in the context of a large-lecture hall, it is very easy for faculty to hold a discussion with only the students in the first few front rows. It doesn’t take too many class sessions before students farther back in the classroom to realize that questions posed by the professors without accountability systems don’t actually need to be contemplated because only the first few rows are required to respond. As a result, some system that holds all students accountable needs to be implemented to be effective. Some faculty draw names at random from a hat to ask specific students questions and evenly ask all students to participate. One popular technique is to write names on popsicle sticks using a color code that distinguishes male names from female names so that faculty can evenly alternative between males and females even though the process appears random to students.
Probably the most easy teaching skill to understand, yet most difficult to actually implement is to ask meaningful questions and then patiently WAIT. The most common error in leading classroom discussions is a lack of wait time. Researchers that carefully track classroom dynamics have found that faculty who too quickly provide clarifying information or respond to the first person who answers a question completely squashes further discussion and divergent thinking. The common advice is to wait at least ten seconds before saying anything after posing a question. If everyone in the audience can answer your question in less than ten seconds, then the question isn’t conceptually challenging enough. When you pose a question, it is reasonable to ask students to think for a little while before raising their hands to offer answers. One particularly useful strategy to help fidgety faculty be certain that a full ten seconds elapses before accepting a range of student responses is to fill the time by turning away from the class, taking a sip of coffee, or flipping through lecture notes without looking at the class. Moreover, it is important to ask students to explain the reasoning behind their answers and not revealing if the offered response is correct before accepting several other answers.
University of Wyoming CAPER Team
Tuesday, February 26, 2008
It is generally accepted that successful science education results in learners developing a meaningful understanding of the nature of science. In fact, the various guidelines for what should be taught in introductory science courses throughout the educational levels uniformly state that students should develop an understanding of the nature of science (viz., AAS, AAAS, NSES, SCST). According to these documents and position statements, students who understand science know that scientific knowledge is based upon evidence generated through experimentation and evidence, that science is a process that uses models to make predictions about natural phenomena, and that scientific theories are tentative subject to additional evidence, often resulting from advances in technology. In the same sense, these authors suggest that one might further expect students to understand that science is fundamentally a human endeavor and is enhanced, as well as constrained, by societal values and technology.
If one agrees that enhancing students’ understandings of the nature of science is an important goal of science education, the next thing one wonders is how best to teach students these ideas. Along a continuum of ideas, one perspective might be that simply by students being exposed to and memorizing the methods and results of astronomical inquiry over the duration of a course, that students should intuitively develop an accurate sense of the nature of science. However, a robust research agenda by Norm Lederman and his colleagues (viz., Lederman, 1999 and references therein) argues that students do not develop deep understandings about the nature of science unless the underlying ideas are taught explicitly. Indeed, a cursory survey of the introductory chapters of typical astronomy textbooks suggests that students should learn about the components of scientific inquiry nearly independent of the context of astronomy. Many textbooks bold-face such key terms as hypothesis, theory, law, and experiment/observation are included as definitions in end-of-book glossary entries—BUT, these same texts rarely use such words ever again in the textbook after the introductory chapters.
A long-standing strategy for teaching students about the nature of science, and the process of scientific inquiry has been to assign students the task of completing a “science fair” project. In its most abstract form, students are commonly asked to first create a hypothesis, conduct background library research, design an experiment with controlled variables, manipulated variables, and responding variables, summary their results in a table or graph, and create a conclusion about the veracity of their proposed hypothesis. (In the absence of systematically gathered data, I submit to you that these components are those commonly found on the judges’ scoring forms for many secondary-level science fair competitions.) In support of students conducting science fair projects, numerous web sites and books have been written that go through these steps in sequence, starting with generating a question and writing it in the form of a testable hypothesis, and ending with a conclusion that uses data to support or reject the hypothesis.
Upon reflection, one wonders if a ‘backwards’ approach, based on the pedagogical notions of faded scaffolding proposed by Marx and his colleagues (Krajcik et. al., 1998) might be more effective at helping students develop a deeper understanding of the nature of science consistent with the aforementioned science education reform documents. In other words, instead of describing first the character of an if-then-because hypothesis followed by explaining the process of fair-testing by collecting data through appropriate experimental design, then ending with how to write a formal conclusion statement, what would happen if the instructional sequence was to provide students with scenarios starting with an entire inquiry sequence, then piece by piece, start replacing ideas from end-to-beginning? Perhaps a simplistic, yet illustrative, example might serve to clarify this notion.
Question Res. Procedure Data Collection Conclusion
1 Given Teacher Given Teacher Given Given
2 Given Teacher Given Teacher Given Created
3 Given Teacher Given Created by Student Created
4 Given Student Created Created by Student Created
5 Created Student Created Created by Student Created
ILLUSTRATIVE EXAMPLE – MOTION OF THE SUN
STEP ONE: Students are shown a desktop planetarium program projection of the Sun’s daily motion through the sky at the equinox and asked to record the exact azimuth at which the Sun rises on the equinox in order to systematically collect data and use observational evidence to answer the question, “Does the Sun rise directly in the East on the first day of spring?” Note, the question, the research design/procedure, the data, and even the answer is provided to the students.
STEP TWO: Students are shown a desktop planetarium program projection of the Sun’s daily motion through the sky at the equinox and asked to record the exact azimuth at which the Sun sets on the equinox in order to systematically collect data and use observational evidence to answer the question, “In what direction does the Sun set on the first day of spring?” Note, the question, the research design/procedure, and the data is provided to the students, but NOT the answer.
STEP THREE: Students are shown a desktop planetarium program projection of the Sun’s daily motion through the sky at the equinox and asked to record the exact times, azimuth, and altitude of the Sun at rising, transit, and setting on the equinox in order to systematically collect data and use observational evidence to answer the question, “What is the altitude of the noontime Sun on the first day of spring?” Note, the question and the research procedure are provided to the students, but NOT the data collection nor the answer.
STEP FOUR: Students are shown a desktop planetarium program projection of the Sun’s daily motion through the sky and asked to create a list of observations they would need to make and record (an experimental procedure) in order to collect data to answer the question, “how does the Sun move through the sky on the first day of winter?” Note, the question is the only thing given by the teacher, whereas the data collection procedure and the answer must be generated by students.
STEP FIVE: Students are given access to a desktop planetarium program projection of the Sun’s daily motion through the sky asked to create a list of questions they could answer by planning a set of observations they would need to make (experimental procedure) in order to answer their question. Note that it is unlikely that students would pick questions far afield from the domain for which they have had four previous experiences – in this sense, although this meets the spirit of “open inquiry,” the activity falls within the overall conceptual domain of motions of the heavens. For certain, one might wonder if this approach requires significantly more time to instruct students than it would if one had given students a series of steps to follow or even simply demonstrated these ideas to students. I submit it takes considerably more time to teach in this manner; however, the goal here is to facilitate students to learn about the nature of scientific inquiry simultaneously, and perhaps superlative to developing students’ understandings about the motion of the Sun.
It seems to me that students do need help with understanding each of the components of scientific inquiry, as an important and simultaneous part of learning how to conduct scientific inquiry where: (i) students are engaged in questions; (ii) students are designing plans to pursue data; and (iii) students are generating conclusions based on evidence they have collected. Therefore, I propose that a series of exercises might help students to understand the nuances of each component in the following ways.
(A) students are generating to conclusions based on evidence
In each case, are the conclusions sufficiently justified by the evidence presented?
1. Polaris, the North Star, never rises and sets because observations reveal that it is visible in the same location any clear night of the year and any time of the night.
2. Solar eclipses are caused by our Moon blocking our view of the Sun based on the evidence that this only occurs during new moon phases when the moon’s path is close to the ecliptic.
3. Jupiter must be physically larger than Saturn because Jupiter takes up more of the field-of-view in the telescope eyepiece than Saturn does.
4. Pluto is not a planet because it has no life nor any liquid water on its surface.
(B) students are designing plans to pursue data
In each case, will the research design created answer the question posed?
1. To determine when the Sun will set on June 1, we will record the setting times on March 1, April 1, and May 1 and extrapolate.
2. To determine how long it takes the Jupiter to rotate on its axis, we will record the apparent longitudinal position of the great red spot every hour throughout the night.
3. To determine the azimuth (direction) the Sun sets, we will observe its highest altitude every day.
4. To determine the temperature of the Sun, we will measure the temperature of a glass of water achieves after being illuminated by the Sun all day.
(C) students are engaged in questions
In each case, determine if the question is scientific?
1. What time will the Sun set on my birthday?
2. How much larger does the Sun appear to be in the sky than the Moon?
3. Pluto is a planet?
4. Did God make the Sun spin?
In science education circles, people often speak of a continuum of student experiences ranging from step-by-step cookbook laboratory verification exercises, guided-inquiry experiences, to open-inquiry experiences. For the purposes of this discussion, I am defining open scientific inquiry as the process by which students are (i) engaged in questions; (ii) designing strategies to pursuing data; and (iii) generating and defending conclusions based on evidence they have collected. There seems to be considerable reluctance for teachers to “turn students loose” to pursue whatever they please in open-inquiry learning experiences. However, when using a backwards, faded scaffolding approach as outlined here, student inquiry is specifically, yet quietly, channeled into conceptual domains consistent with a teachers’ curriculum and instructional goals. Most importantly, the focus here is on scientific inquiry, rather than on memorizing the facts and figures of science. As such, it just might be that science becomes more attractive to individuals who often have the perception that science is boring rather than a creative endeavor worth pursing with intellectual energy.
American Astronomical Society Position Statement on Introductory Astronomy Courses as reported in Partridge, B. & Greenstein, G. (2003). Goals for "Astro 101": A report on workshops for department leaders, Astronomy Education Review, 2(2).
American Association for the Advancement of Science. (1993). Benchmarks for Science Literacy. New York: NY: Oxford University Press, Inc.
Krajcik, J., Blumenfeld, P. C., Marx, R. W., Bass, K. M., Fredricks, J., & Soloway, E. (1998). Inquiry in project-based science classrooms: initial attempts by middle school students. Journal of the Learning Sciences, 7(3-4), 313-350.
Lederman, N. G. (1999). Teachers’ understanding of the nature of science and classroom practice: Factors that facilitate or impede the relationship. Journal of Research in Science Teaching, 36(8), 916-929.
National Research Council. (1996). National Science Education Standards. Washington, DC: National Academy Press.
Society of College Science Teachers Position Statement on Introductory Science Courses retrieved from www.nsta.org
Many of these ideas are the direct result of extended conversations with Stephanie Slater, University of Wyoming CAPER Team.
Tim Slater, University of Arizona & University of Wyoming
Cognition in Astronomy, Physics, and Earth sciences Research (CAPER) Team
Wednesday, February 13, 2008
Off hand essay on engaging students to think about finding life beyond Earth...
Often when giving public talks on astrobiology and searching for extraterrestrial life, an oft posed end of lecture question is, “why are we looking for bacteria instead of for living things?” Now, I know this is a common question, so I try to make a big deal out of bacteria being alive – being organisms that take and recycle energy from their environment, alter their environment by their being there, and reproducing. I also talk about how surprising it is that bacteria can thrive in more exotic environments than humans can (aside from the jokes that thermo-philic people live just fine in both extremes of the heat of Tucson, AZ and the cold of Laramie, WY). Yet, people often ask. Perhaps it is because they’d rather NASA wasn’t spending their tax dollars on looking for “lesser” forms of life or perhaps they don’t really believe bacteria are alive – either way, it is a definite sticking point.
In pondering how to get around this while giving classroom lectures in Hilo last week, it occurred to me to try something new. I asked seventh grade students at the beginning of my classroom visit to “imagine they were an astronaut being sent to a newly discovered planet where life existed – and to creatively draw what creatures they might find there and to provide three important facts about these new life forms.” You might imagine what students drew—nearly 100% drew anthropomorphic things with arms, mouths, eyes, and legs.
So, even before I began my “lecture,” I polled students to raise their hands and how many drew something with eyes? Then I said, could several people give me examples of living things on Earth which have eyes—which many could do. Then I said, ok, could you give me some examples of living things on Earth which do NOT have eyes. It took students a few moments, but eventually, they listed trees and worms (and of course bats and sharks were mentioned too as having lousy eyesight – glad they didn’t point to my thick glasses!). I said to them, “hum, curious, I wonder if there are more living things on Earth with eyes or withOUT eyes?,” and left the question unanswered.
Then, I went through the list – examples of things on Earth with mouths, then without mouths, and then do you think there are more living things with mouths or without mouths on Earth? Followed by the same dialogue about arms and legs.
At this point, it seemed to me that many students were on the verge of considering that maybe most things on Earth don’t look like people with eyes, mouths, arms, and legs – but to be sure, I went in for the kill. I said, “well, let’s change the challenge for a moment to say, ‘imagine you are an alien from another planet sent to land on Earth and look for life…if you just landed at some random spot on Earth, would you land in the water or on land? Hum, well if you landed at some random spot on Earth, how likely do you think you could look around and see a person?” Well, to my great surprise, this didn’t seem to seal the deal as well as I thought.
So, in desperation, I grabbed an inflatable beach-ball globe of the Earth, I and started randomly tossing it to students. I said, “imagine you landed where your right thumb is, would you likely look at the window of your space craft and see a person?” And, I kept a tally on the white board of person or no person, while the students tossed the ball around to other students and yelled out the answer. Well, you know where this is going, after 15 or so tosses, when the throwing got extreme, it was clear that most of the time, a randomly landing thumb (alien space craft) didn’t hit land, let alone a population center. Now, this was the culminating piece of evidence for majority of the students – aliens might not even know there were living things with eye, mouths, arms, and legs if they visited Earth unless they were lucky. And, this, of course, supports the notion that when we go to other planets, we need to be open minded about what life there might look like and it probably doesn’t look much like us.
I hope that my luck with this continues, and that if you try this with your students, it works well too!
Clear Skies, Tim
Tim Slater, CAPER Team
University of Arizona and heading to the University of Wyoming
Check out the silly press release: http://www.uwyo.edu/news/showrelease.asp?id=20440
And write me firstname.lastname@example.org
Monday, January 14, 2008
This month, AER published a paper by Kristine Larson on the use of the word “believe” (she refers to it as the “b-word”) in the science classroom. Larson’s article contains a discussion of the abundant misuses of “belief” in the lay presentation of science, including examples of “theological handwaving” by many of the successful popularizers of physics and astronomy.
Larson’s argument is that when scientists, science articles and science textbooks, use the words “believe” or “belief” (e.g. “Biologists believe that evolution is the best explanation for the development of life.”), it is confusing to the general public and to students. She says that the overuse of the word itself may contribute to a general sense of relativism among students: that science and religion are both “belief” systems, and you can’t know if either is right.
Larson demonstrates the entrenchment of the “b-word” in popular books, articles and textbooks. Her article’s main suggestion is that we should be removing the word from our explanations of science. I agree.
Science is in the business of developing models of the world. Accurate models are the ones that can survive repeated testing in experiments and against observations. For this reason, I think teachers should be constantly referring to the ideas of science (e.g. the Big Bang, General Relativity, Newtonian physics, etc) as models. Every time a model is discussed, we should refer to the observational/experimental evidence for it.
For several years now, I have consciously tried (as Larson suggests) to “ban the b-word” from my classroom speech. Rather than say: “Astronomers believe that…”, I find it better to say “Astronomy have confidence that…”. The distinction may seem small, but in the minds of students, semantics is important. In all of the science courses I teach (not just astronomy), I make it a point to go over several words that scientists use differently, such as “belief”, “theory”, “hypothesis”, “argument”, etc. I model my discussion after a chapter in a short book on science philosophy entitled "Just A Theory: Exploring the Nature of Science” by Moti Ben Ari. The chapter is called “Words Scientists Don’t Use: At Least Not the Way You Do” and is entertaining and accessible enough to assign as a reading for students.
When it comes to all the models that we sometimes hear referred to as “just a theory”, I have a favorite tactic: in addition to using the word “confidence”, I also point out the implications if these ideas were not accurate. Students (and people in general) often do not look for evidence that refutes their ideas or hypothesis, so I think it is important to constantly point out alternate outcomes and predictions.
For example, I like to point out that if general relativity were not an accurate model of nature, then global positioning systems would not work as well as they do. If special relativity were “just a theory”, then many of us could not flip the switch on the wall and expect the lights to turn on (since nuclear power accounts for a good portion of electricity generation in the US). If evolution through natural selection were not a good model of biology, then you might as well stop taking antibiotics.
When confronted with concrete applications of a model, I think that students will be more accepting later on when it comes to further implications of the same model. Accepting the expanding Universe model may be easier when students understand the observations that lead to it; even easier when they realize that redshift observations use essentially the same experimental (though not conceptual) physics that police radar guns use.
Larson’s article on the “b-word” ends with a bit of action research she did with a small class of non-major honors students. She gave her class the following open response question:
“You tell your roommate about this course, and they say "I don't believe in the Big Bang. It's just some stupid theory and there's no evidence for it. Besides, you can't believe in God and the Big Bang." How would you use what you have learned in this course to counter all parts of their argument?”
Larson’s description of the disappointing results is not surprising. Even though the question has explicit instructions to counter “all” parts of the argument, it seemed few of the tested students did so. Her sample comes from a non-major class on science and science-fiction, and she does not gives us many details about the class organization, goals, or pedagogical style, except that they discussed the concept of “non-overlapping magisterial” and the Big Bang model. Even so, I would not be surprised to see similar results in many intro astronomy courses. In the past, I have used questions not-unlike Larson’s on exams. Recently, however, I have used almost completely multiple-choice exams in astronomy. But, as Larson points out at the end of her paper, such assessments can easily fail to demonstrate whether or not a student can articulate the difference between a scientific theory and a belief.