Browsing the Journals
Thomas D. Rossing
· Resistance to certain scientific ideas derives in large part from assumptions and biases that can be demonstrated experimentally in young children and that may persist into adulthood, according to a review in the 18 May issue of Science . Both adults and children resist acquiring scientific information that clashes with common-sense intuitions about the physical domain. Babies know, for example, that objects are solid, persist over time, fall to the ground if unsupported, and do not move unless acted upon. The problem with teaching science to children is not what the student lacks, but what the student has, namely alternative conceptual frameworks for understanding the phenomena covered by the theories we are trying to teach.
· The April issue of American Journal of Physics has a resource letter on "Physics and society: Energy" that provides a guide to the physics-related literature about energy and society. One way to teach energy and society is to develop an entire course devoted to the topic. Another way is to insert energy-and-society topics into a more general physics course. Journals, textbooks, and websites are referenced on a variety of topics including fossil fuels, global warming, nuclear power, fusion power, renewable resources, wind, photovoltaic, and geothermal energy, and energy storage.
· Teacher turnover, which is "spiraling out of control," is estimated to cost the nation more than $7 billion a year, according to a story in the June 20 issue of Education Week . A study by the Washington-based National Commission on Teaching and America 's Future says that despite the staggering expense, virtually no school district has systems in place to track or control such turnover. Turnover costs are based on expenses incurred to recruit, hire, and train teachers. The report recommends that the federal government make retention of highly effective teachers a focus of the No Child Left Behind Act, which is up for reauthorization this year.
· "Three or four golden rules of lecture" is the title of an article in the April issue of The Physics Teacher by a recent recipient of the AAPT award for excellence in undergraduate teaching. Rule 0: Reinvent as little as possible. Learn from your peers, read the literature. Rule 1: Emphasize conceptual understanding and qualitative reasoning throughout the course, especially on the exams. Rule 2: It is OK to lecture less, because they are not listening anyway. Rule 3: Class morale is vital. If the students learn some physics but leave class hating the subject, we have failed.
· The impact of teaching assistants on student retention in the sciences is the subject of an article in the March/April issue of the Journal of College Science Teaching . The authors present results from a survey of 2,100 undergraduates that, contrary to previous research, suggests that teaching assistants influence student retention in the sciences in multiple ways. Multiple linear regression and student comments suggest that TAs influence lab climate, course grades, and students' knowledge of science careers, all of which have an effect on students' decisions to stay in or leave science. The article presents some recommendations for TA training, mentoring, and management.
· The merits of programs aimed at attracting more women into physics should not be judged purely on enrolment statistics, argues a forum comment in the April issue of Physics World . Our goal should instead be to allow women to choose their career with as much freedom as possible. "Manipulating a person towards science is not any more acceptable than manipulating that person away from it."
· "The special joy of teaching first year physics" is the subject of a guest editorial in the July issue of American Journal of Physics. A number of circumstances make the first year so special. Students enter the university with great expectations, they respond to good teaching, and their learning ability appears to be at a maximum. The usual first year fare---which includes Newtonian mechanics and electromagnetism-allows them to reach great heights in science. All physics departments should capitalize on these circumstances. It is a special joy to hear from former students about the impact my physics course has made in their lives.
· "The advanced laboratory experience plays a pivotal role in undergraduate physics, yet it is often taught in isolation," observed former AAPT president Dick Peterson in the March/April issue of Interactions , a new AAPT publication. Typically advanced laboratories, taught at the junior or senior level, include experiments from atomic and nuclear, condensed matter, optics, fluids or acoustics. Sometimes advanced laboratory experiences are incorporated within upper-division courses, sometimes they are stand-alone courses. To foster a continuing conversation on topics related to advanced labs, AAPT has established a listserv at www.aapt.org/advlabs . This website includes links to other valuable material on advanced laboratories.
· An article called "Nature's guide for mentors" in the 14 June issue of Nature has an interesting discussion of mentoring and how to be effective mentors. Personal characteristics of effective mentors include: enthusiasm, sensitivity, appreciation of individual differences, respect, unselfishness, and support for other than one's own students.
· A guest editorial "Why physics first?" by a high school teacher appears in the March issue of The Physics Teacher. Although one of the most common arguments for physics first is that it prepares students to study chemistry and biology, the author argues that a more fundamental reason is that it exposes more students to physics. He teaches a course in conceptual physics to ninth graders, most of whom will never take another physics course in their lifetime. How can students be considered educated without knowing how and why objects move? What heat really is? What comes out of an electrical plug? How we can explain sunsets and rainbows and echoes? How can we critically evaluate the need to stop global warming?
· A thoughtful essay on teaching for understanding appears in the May/June issue of the Journal of College Science Teaching. The author begins by describing a class he observed. The instructor focused on terms, theories, and mechanisms, carefully answered all student questions. About halfway through the hour, the class broke into "co-operative-learning" teams at which students reviewed their notes together, asked questions of their teammates, and discussed the assignment. During the group work, the instructor visited each group to answer question or rectify misconceptions that came up. On the surface the teacher had done a commendable job. What was missing, however, was the application of the principles in the lesson to different situations that promote understanding.
How can professors teach for understanding rather than memorization? Our ancestral scholars achieved teaching for understanding by responding to the pupils' questions not with answers, but with other questions. A lasting knowledge can be achieved by applying a simple learning cycle, developed 40 years ago by Karplus and Their. The three phases of the learning cycle are explanation, comprehension, and application. Understanding, not facts, is what education is all about.
· The physics education systems in Holland , Russia and America are compared by a student who experienced all three in the March issue of The Physics Teacher. He attended elementary school in Russia and high school in Holland and the United States . In his opinion the main advantage of the American education system is the possibility to choose subjects according to your interests and your level. He found his physics classes interesting but found the problems did not require intensive thinking and standardized tests checked mainly memorization. In Russia the demands of math and science courses are very high and there is no avoiding them even if you do not plan to pursue a career in science. Dutch students focus on language, and after VWO (pre-university) school, students speak four or five languages.
· "Dilemma of a science educator" is the title of an essay in the May issue of Physics Education. The author says that when he was at university, the best way to get a decent mark in a physics practical was to rig the results. There was no way-using the apparatus provided-to get anything like the answer in the textbook. Components were missing, instrument needles were sluggish with rust, batteries were flat and crocodile clips were bent beyond usefulness. But as students mysteriously produced ever more accurate results, there was no reason for the lab technicians to check on the quality of the apparatus. And so the vicious circle continued. The way to pass was to work backward. First you looked up the answer in the book, then drew the appropriate straight-line graph and scattered some points around it, then finally you deduced what readings you should have taken.
There are many examples in research. About 100 years ago, Robert Millikan devised a wonderful experiment to measure the charge on an electron-by placing charged oil drops into an electric field. Millikan used this method to show that charge does not vary continuously, but instead goes up and down in steps-those steps being the charge on one electron. Millikan's method was sound, but, just to be sure that he quelled potential doubters, he was choosey about the results he published. According to a Wikipedia article on this issue, this selectivity 'enabled Millikan to quote the figure that he had calculated e to better than one-half of one percent; in fact, if Millikan had included all of the data he threw out, it would have been to within 2%.
Thomas Rossing is Distinguished Professor Emeritus at Northern Illinois University and a Visiting Professor at Stanford University. His main interests are acoustics, magnetism, and physics education.