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| astro300:f07:aer:lsci [2007/11/05 21:45] – external edit 127.0.0.1 | astro300:f07:aer:lsci [2019/12/16 17:15] (current) – removed nathan_sandford |
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| ====== Development and Validation of the Light and Spectroscopy Concept Inventory (Bardar et al. 2007) ====== | |
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| As the title suggests, this article discusses the development of a new concept inventory to address students' understanding of concepts related to light and spectroscopy. The first author, Erin Bardar is a friend of mine from Boston University, who got her Ph.D. two years ago and is now working for a curriculum development company. She is currently helping develop the first ever astronomy textbook directed at the high-school level. This article, which is adapted from parts of the first author's dissertation, describes the development process for the Light and Spectroscopy Concept Inventory, and does not address the findings of their research on the relative effectiveness of different teaching styles. I want to first just give a quick summary of the parts of the research this article does address, and then give further information on the research, based on talking to Erin. | |
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| ===== Article Summary ===== | |
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| The article motivates the need for a Light and Spectroscopy Concept Inventory (LSCI) as these concepts are so central to the field of astronomy. I would agree that an understanding of the nature of light and spectroscopy is essential to understanding how any of our knowledge of the cosmos is attainable. It is interesting that this topic is one that students have particular difficulty with, since I would guess there are relatively few ill-conceived notions about light, other than the terrestrially prevalent idea that red is hot and blue is cold. However, I have indeed found Astro C10 students are slow to grasp the applicability of different concepts (i.e. Doppler shift, Wien's Law, etc), perhaps because their understanding gained through lecture-based instruction is so shallow that they are almost guessing as to when different things are relevant. The article also addresses the development of distractors through student-interviews, and the authors point out the importance of writing distractors in "the students' natural language" so as to really get at any misconceptions. I assume this means using slightly modified versions of incorrect student responses from the interviews as bases for the distractors. There is also a good discussion of the utility of multiple-choice concept inventories, as it's not immediately clear that these would penetrate beyond "factual recall," but I find the discussion fairly convincing. | |
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| The questions developed were then vetted by a group of "experts" before being used with a set of 50 students in the BU equivalent of Astro 10. Four questions were immediately obvious to students even on the prettest, and an additional question was found to be ambiguously worded. These were heavily modified prior to the larger scale field test of the LSCI. I like that some of the questions failed at first because it highlights what we discussed last week, when we talked about the differences between experts and novices. The experts thought they had the right set of questions, but really did not have a good understanding of what novices might mistake. Perhaps it would have been useful to have a set of former students of Astro 100 in on the development of the LSCI in the first place? The section on the field test mainly describes some of the less interesting logistical details of administering the test. However, some points of interest also appear in this section. First, the total number of students involved is given: 548 pre-instruction and 368 post-instruction. Second, the "active engagement" courses include either peer instruction, Lecture Tutorials, or homelabs. While peer instruction is a fairly obvious type of active engagement, the other two are less obvious. According to the referenced article by Prather et al., which can be found [[http://aer.noao.edu/cgi-bin/article.pl?id=132|here]], lecture tutorials are sets of worksheet like materials which are used during lecture to help students get actively engaged in the material just presented in lecture (I read some of the Prather article and it seems interesting). I'd present an example, but these are now [[http://www.aw-bc.com/catalog/academic/product/0,1144,0132392267-FDOC,00.html|published by Addison-Wesley]] and therefore not free. It sounds though somewhat like the worksheets we use in sections, but perhaps shorter and written in a different style. The homelabs are the Project LITE materials which I talk about in the next section. They are, just as they sound like, a set of labs students can complete at home, which let them interact with material on light and spectroscopy. | |
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| Finally, the article discusses how the utility of the LSCI questions was analyzed. First, the difficulty was analyzed in hopes of weeding out questions which addressed test-taking ability rather than conceptual understanding and those which were poorly worded or otherwise unnecessarily confusing, regardless of the student's understanding. Second, they analyzed the ability of a question to discriminate between relatively high and low scoring students. That is, they addressed the question: is this student's understanding of this question indicative of his or her overall level of understanding, or is there something else going on? The test overall was also examined for internal consistency and validity (i.e. does this test, as a whole, highlight student's level understanding in the concept domain it purports to?). The answer to these questions seems to be yes, so that's good. However, the LSCI is not yet perfect, and requires further testing to determine the validity of //all// of its items. In the final section, the article indicates that the use of the LSCI as a test of the effectiveness of different teaching styles will be examined in future articles, which are not yet published. I will give some information on those as yet unpublished results in the next section. | |
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| ===== Beyond the Article ===== | |
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| The LCSI was used, as the article mentions, to address the relative effectiveness of different teaching styles. Erin tells me that the articles describing these findings have been submitted, and should be appearing soon. The teaching styles were split into two very broad categories: classic lecture style and "active engagement." In agreement with the other findings we've read about, interactive teaching styles lead to (statistically) significantly better comprehension of the material than lecture-based courses. One of the active engagement courses was a lecture-based course that involved the use of a set of take-home interactive lab materials on light and spectroscopy concepts. Erin tells me that this course (which was taught by her adviser) also led to better student understanding of the LSCI concepts. The interactive lab materials are being developed as part of "Project LITE," which can be found [[http://lite.bu.edu|here]]. I'm not sure exactly how the materials were used, but they are being developed by her advisor, Ken Brecher, and others as a useful set of tools to aid student learning in settings where lab equipment is not readily available; much of the interactive stuff requires only a computer. I'm also guessing that the instructor either uses the stuff for in-class demonstrations, or provides students with guidance as to which materials are most relevant during different parts of the course. I found this interesting in that instructors who are reluctant to change their lecture-based courses might be able to get some of the benefits of a more interactive class simply by introducing more interactive labs. | |
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| The LCSI itself can be found [[http://aer.noao.edu/auth/LSCIspring2006.pdf|here]] for those that are interested. | |
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| --- //[[jhshiode|Josh Shiode]] 2007/11/05 13:43// | |
