Using Concept Maps To Teach a Nanotechnology Survey Short Course

In The Classroom edited by

Boyd L. Earl

Using Concept Maps To Teach a Nanotechnology Survey Short Course

Department of Chemistry University of Nevada-Las Vegas Las Vegas, NV 89154-4003

David D. Moyses, Jennifer L. Rivet, and Bradley D. Fahlman* Department of Chemistry, Central Michigan University, Mt. Pleasant, Michigan 48859 *[email protected]

The burgeoning field of nanotechnology is an increasingly popular topic for undergraduate coursework. The predominance of nanotechnology in the media, which has associated the term “nano” with sleek, lightweight, and technologically advanced consumer products, fuels an almost unprecedented level of student interest for any proposed course syllabus in the nanoscience area. Central Michigan University has recently offered Introduction to Nanotechnology, a 4-week short course, as part of a series of first-yearlevel courses covering a variety of current topics. Whereas students enrolled in semester-long courses are able to cover nomenclature, synthesis, and characterization of nanostructures, offering a short course in a broad field such as nanotechnology is an ambitious proposition. Such a course has the strong potential to result in a high degree of frustration and low degree of learning as students are inundated with an overwhelming number of new concepts and terms. Indeed, the problem of where to begin and where to end is paramount in any short course; this is perhaps an even greater problem for a topic in which students have no prior related coursework experience. To continue evolving the course in a way that best promotes students' learning, it would be instructive to have a simple means of evaluation to determine how much is too much. Here we describe the use of student-generated concept maps to gauge the level of conceptual understanding for each topic covered in the course. Since the first implementation of concept maps by Novak and co-workers in the mid-1980s (1, 2), this pedagogical tool has been widely used to assess the degree of student learning in a variety of curricula (3). In particular, for science-related coursework, there are numerous precedents for the successful use of concept mapping to aid conceptual understanding; for example, use in chemistry (4-10), physics (11, 12), and engineering (13) courses. To our knowledge, there are no reports of using concept mapping for broad interdisciplinary topics, as well as for short courses, where the fast pace dictates the use of facile means to monitor student conceptualization. Most studies have used an interview format to construct concept maps in order to determine conceptual links that were based on prior knowledge from previous coursework (8, 14-17). However, the format of our short course was most conducive for student-generated mapping. Students had no previous coursework related to nanotechnology, precluding the use of constructive prior conceptual links. In addition, there was ample opportunity for students to reflect on the enormity of terms discussed during the weekly lecture and carefully construct concept maps.

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Methodology A total of 10 students were enrolled in the one-credit course, Introduction to Nanotechnology, during the Spring 2008 semester at CMU. The class met once a week for 3 h, over a 4-week duration of the course. A precourse survey was distributed to ascertain the students' familiarity with nanotechnology. Weekly homework assignments consisted of concept map constructions, covering the following topics: What is nanotechnology? (Week 1); overview of applications for nanotechnology (Week 2); and overview of the health hazards and ethical considerations of nanotechnology (Week 3). The final exam was given in Week 4. The students were instructed to assemble what they perceived to be the main points of each lecture into a meaningful array. Students used a variety of software packages to draw concept maps; for consistency, we transcribed all concept maps into the same format using the Mindnode Pro software package (18). Though a qualitative assessment of concept maps is extremely instructive to identify gaps in knowledge of individual students, we also devised a quantitative scheme for evaluating student arrays. Overall scores were based on the number of terms incorporated, as well as their relevancy to the conjoined topic(s). We evaluated the concept maps using a modified version of that reported by McClure et al. (19), where branches (i.e., propositions) were graded based on their relevance to the connected concept(s). For each concept map, the “overall branch score” was determined by the summation of all individual branches, each assigned a score of 0 (erroneous or irrelevant relationship), 1 (moderate relationship), or 2 (strong relationship). For comparative purposes, each concept map was given a percentage score, based on the following equation: overall branch score=2ðtotal number of branchesÞ 100% Examples of the grading rubric for the first two concept maps will be detailed below, when discussing the relevancy of particular branches. Analogous to term paper grading, there is a certain degree of subjectivity; however, grading by two different faculty members resulted in overall concept map grades within 5% of each other. The overall course grade was based on class attendance and participation in weekly discussions (10%), performance on concept map assignments (40%), and an in-class final exam (see below), which probed students' understanding and application of basic terminology and concepts related to nanotechnology (50%).

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r 2010 American Chemical Society and Division of Chemical Education, Inc. pubs.acs.org/jchemeduc Vol. 87 No. 3 March 2010 10.1021/ed8000914 Published on Web 02/09/2010

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Journal of Chemical Education

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Results and Discussion We surveyed the students during the first class to determine their background level of understanding related to nanotechnology. The five questions that follow were posed to the students; characterizations of their responses provide a context for interpreting the concept map results. Question 1: What Is Your Major? The 10 enrolled students majored in chemistry, information technology (2), child development, biomedical science, biology, communication disorders (2), computer science, and meteorology. Question 2: Where Have You Heard of and/or Read about “Nano” or “Nanotechnology”? Not surprisingly, each student has his or her own frame of reference for nanotechnology. The computer science and IT majors cited “size of computer chips getting smaller”, while the chemistry and biology majors listed information gleamed “from previous classes and laboratory”. Among the science majors, sources included “magazines (Time, Scientific American)” and “television”. The three nonscience majors did not have much exposure to nanotechnology; one student mentioned “kind of heard about nanotechnology on PBS”, whereas the others did not have any knowledge or background and were looking forward to learning more about this topic based on the interesting course description.

Assessing Students' Concept Maps

Question 3: How Would You Define “Nanotechnology”? Definitions from the science majors included phrases such as “applications involving tiny components”, “very small and precise things for technology and devices”, “microscopic”, and “technology at the molecular scale”. Two science majors also mentioned the size regime of “billionth of a meter”. The nonscience majors were less precise, citing the popular media description of “high technology”, and “advanced technology involving chemistry”. Question 4: What Applications Are Possible for Nanotechnology? Whereas the nonscience majors did not offer any applications, the science majors listed items related to their major (e.g., meteorology major, “meteorological radar and modeling of tornadoes”; chemistry major, “more efficient solar panels”; IT major, “faster computers” or “faster/better circuits”). Two students cited general statements of “better technology and ability to do things that were not possible before” (IT major) and “endless possibilities related to health care and environmental work” (biomedical science major). Question 5: What Are Some Societal Negative Impacts of Nanotechnology? This is a question that most students did not have an answer for, which seems to reflect the popular media focus on the applications of nanotechnology. One student listed “being more dependent on technology to live” as a negative, whereas a computer science major listed “things getting so small that some day we will all have microchips in us”. Two other students listed “pollution”, without any further description. 286


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Vol. 87 No. 3 March 2010

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Figure 1. Student-generated concept map in response to the question: what is nanotechnology? This map illustrates a clear organizational framework for basic concepts; the quantitative score was 75/82 = 91%.

Mapping Nanotechnology Definitions A qualitative assessment of concept clarity may be easily determined from the number of multiple branches, and overall complexity of the concept array. For example, consider the concept maps from two students regarding the definition of nanotechnology (Figures 1 and 2). From a gross evaluation of these arrays, it is obvious that one student (Figure 1) has gained a more lucid understanding of nanotechnology terminology. In particular, most primary branch units (categories, applications, forms, and nanomaterial) represent logical components of the broad concept of nanotechnology. It is evident that this student understands the two forms of nanomaterials (0-D and 1-D), as well as some examples for each. However, this student does not appear to fully understand the context of nanomaterials (i.e., nanomaterial and forms listed as separate branches rather than a single node). The last primary branch (modern nano) is a rather unclear designation, which elucidates some deficiency with understanding the historical context of nanotechnology as well as the nature of fullerenes (listed as an application, rather than a form). Regarding the grading rubric for this map, 1 point (relatively weak relationship) was subtracted for each of the following branches: modern nano branch, fullerene (should be placed under 0-D forms, but is an example of a modern nano architecture), and solution phase (which should be placed under bottom up > chemical synthesis; however, the subbranches of dendrimer entraining agents are examples of modern nano synthetic techniques). Each of the following terms had two points deducted: application (redundant branch), and colloids (not modern; should also be placed under 0-D forms). Because this concept map had 41 total branches with a possibility of 82 total points, the score was 75/82, or 91%.

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r 2010 American Chemical Society and Division of Chemical Education, Inc.

In The Classroom

Figure 2. Student-generated concept map in response to the question: what is nanotechnology? This map illustrates problems with concept organization; the quantitative score was 51/66 = 77%.

In contrast, the concept map shown in Figure 2 demonstrates significantly greater knowledge gaps. This student has chosen to divide nanotechnology into (counterclockwise, from bottom right) nano architectures, nanocluster growth, nano, fullerenes, and 3 categories. This immediately points out the lack of understanding of nanoarchitectures, of which fullerenes and nanospheres should both be placed as subbranches. The primary branch of nano appears to be an agglomerate of architectures (nanoprism and nanosphere are listed as subbranches), synthetic strategies (subbranches of top-down and bottom-up), and even consumer products and applications (subbranch of iPod Nano). Further, the primary branch of 3 categories (referring to various nanoapplication foci) was placed above applications; clearly, these two should be reversed. However, this student appears to have a clear idea of metallic nanocluster growth, which requires an entraining agent and reducing agent. Likewise, this student realizes that there are three categories of nanotechnology: radical applications are correctly described as being technology that is new/recent and futuristic in nature (though no examples are given). Regarding the specific grading rubric for this map, out of a possible 66 points (33 individual branches), 1 point (moderate relationship) was deducted for nano material, drug delivery, applications, technology, and new/recent branches. Because of erroneous placement or redundant branches, two points were deducted from nanoarchitectures, fullerenes, nano, iPod Nano, and small branches, resulting in a total score of 51/66, or 77%. It should be pointed out that the more lucid concept map was generated by a nonscience major (a student majoring in communication disorders), whereas the more confused organizational motif was generated by a student majoring in meteorology. Hence, this suggests that students need not possess a requisite scientific frame of reference in order to properly understand the multifaceted definition of nanotechnology.


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Figure 3. Student-generated concept map in response to the instruction: summarize the applications of nanotechnology. This map illustrates a very clear conceptual organization; the quantitative score was 114/114 = 100%.

Mapping Nanotechnology Applications Figures 3 and 4 illustrate two student-generated concept maps concerning nanotechnology applications; they correspond to a more lucid understanding and a less clear description, respectively. In Figure 3, the student displays a very clear conceptual understanding of the major classes of applications for nanotechnology, from (counterclockwise, from bottom right) consumer goods, medicine, chemistry/environment, communication, energy, and future applications (including airborne sensors, advanced drug delivery, and computer chip cooling). Another category, referred to as heavy industry correctly shows that nanotechnology will also have an impact on refineries, automotive, and aircraft/spacecraft applications. Indeed, this concept map incorporates many of the important concepts described in lecture, and could be used as an instructor version or master concept map for future offerings of the course. In contrast, Figure 4 shows a greater level of confusion regarding the relevancy of the many terms discussed in lecture. Nanocharacterization techniques such as AFM and STM are listed as primary branches, in addition to quantum dots and band theory. Though these topics were discussed during the lecture in


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Figure 4. Student-generated concept map in response to the instruction: summarize the applications of nanotechnology. This map illustrates a lower degree of conceptual organization; the quantitative score was 96/112 = 86%.

their broadest sense, it is clear that this student with no prior frame of reference had trouble finding the relevancy for these advanced concepts. In addition, a branch labeled better conductivity was linked with semiconductors. This indicates that the concept of size-tunable conductivity of nanostructures was not clearly understood, and this student reverted to logical reasoning that if “nano is better”, it would result in “better” conductivity. Interestingly, this first-year computer science major had many branches related to computer-specific applications. That is, many detailed interconnections were made among integrated circuit fabrication techniques such as photolithography patterning, as well as numerous references to electronic applications; these areas were largely overlooked by most of his peers. Mapping Ethical Implications of Nanotechnology The concept map illustrated in Figure 5 has a relatively small number of branches. However, most of these branches are highly relevant to the discussion of nanotechnology health and ethics, which resulted in an overall high grade. Once again, a number of interesting knowledge gaps are immediately apparent from evaluating this concept map. This student correctly points out a number of ethical implications of nanotechnology, such as equity (i.e., only developed countries having access to this technology), privacy, terrorists, and so on. However, branches that deal with hazards such as human health (safety hazards > health effects) and environmental issues/concerns (safety hazards > environmental impacts) were placed in both health (safety hazards) 288


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Figure 5. Student-generated concept map in response to the instruction: summarize the health hazards and ethical considerations of nanotechnology. This map illustrates a clear conceptual organization; the quantitative score was 62/64 = 97%.

and ethics categories. The moral implications of these branches are not clear as presented. In contrast, Figure 6 shows much more confusion and hype regarding hazards and ethics of nanotechnology. Although


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In The Classroom

Figure 6. Student-generated concept map in response to the instruction: summarize the health hazards and ethical considerations of nanotechnology. This map illustrates a disordered and unrealistic conceptual organization; the quantitative score was 58/80 = 73%.

nanotechnology likely has many unknown consequences that require more research to assess the toxicological and ethical implications, this concept map goes beyond realistic predictions. In particular, branches such as do the impossible, world destruction, break the laws of physics, cloning/genetic manipulation, genetic mutations (with subbranches of unknown evolution and negative changes) are gross overstatements that have been erroneously extrapolated from the course discussions. In addition, organ penetration > heart is listed; however, the toxicological data to date (as discussed in lecture) have shown the accumulation of nanoparticles within brain, liver, and lungs only. Other subbranches such as similar: nuclear fallout, irreversible effects, and especially poor nano creation methods are either misrepresentations of the known effects of nanomaterials, or completely erroneous. Though many branches of this concept map were relevant and conceptually realistic (e.g., the security/privacy subbranches), this map reflects a sentiment of extremely dire consequences that have often been presented by media reports. Interestingly, more than half of the class chose to focus on similarly farfetched implications of nanotechnology, where physical laws are violated, world destruction ensues, or evolutionary consequences arise. Only two students chose to include possible solutions to these issues (more research/funding, standardized fabrication, and handling/waste protocols, etc; maps not shown).

Table 1. Correlation between Students' Concept Map Grades and Final Exams Grades Concept Map Average Scores (%)


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76

72

92

90

84

89

71

67

89

84

97

92

80

86

88

91

72

66

86

83

1. How could nanotechnology be used to solve the energy crisis? (This question included a description of the current problem, what nanomaterials could be used, and the benefits of using nanomaterials vs bulk materials.) 2. What would be the uses of nanotechnology for military applications? (Students were asked to consider those applications not directly related to soldiers' protective gear, which is the most obvious application.) 3. How could the Department of Defense detect and counteract nanosized warfare devices that might be used by future terrorists?

Final Exam Questions The final exam had two parts: an in-class exam that tested student knowledge of basic nanotechnology concepts (e.g., nomenclature, synthetic methods, characterization techniques), and a take-home portion that led students to Web sites and literature to appropriately apply their knowledge. For the latter portion, students were asked to answer these three questions:

Final Exam Scores (%)

As expected, we observed significant diversity in the complexity and breadth of the responses to the take-home questions. However, it is worth noting that both nonscience and science majors did equally well on both portions of the final exam. Table 1 lists the students' average concept map scores and final exam grades. A strong correlation between these grades


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exists, which indicates that concept maps represented an accurate evaluation of their conceptual knowledge. Overall, especially considering the diverse backgrounds of the students, the relatively high grades show an impressive level of organization for a new field of study with its many new terms and concepts. Student comments were extremely positive following this short course. For all but one student, this represented their first opportunity to design concept maps. Without exception, the students strongly believed this exercise helped them to learn. In addition, even though many felt that an overwhelming number of new terms and concepts had been covered in the short course, they indicated that this course would have been much more difficult without the use of concept mapping. Summary Though the student concept maps reveal some knowledge gaps, students were able to incorporate a large number of nanorelated concepts into a logical arrangement. This indicates that, even with little or no previous relevant coursework and a rapid, short-course time frame, students were still able to assemble key concepts in a meaningful way. The final exam scores correlated well with the grades of individual concept maps, which may directly indicate the degree of student conceptual understanding for various topics. Of course, another explanation may be that the students who performed well on concept mapping assessments are high achievers, who also perform well on conventional examination-based assessments. To better assess the effectiveness of concept mapping with respect to enhancing student performance, we plan to continue these investigations with larger numbers of students in other regular-semester, threecredit courses, at both the first-year level and graduate levels. Literature Cited 1. Novak, J. D.; Gowin, D. B. Learning How To Learn; Cambridge University Press: Cambridge, MA, 1984. 2. Novak, J. D.; Gowin, D. B.; Johansen, G. T. Sci. Educ. 1983, 67, 625–645. 3. For a recent review of digital concept mapping models, see: Tergan, S.-O.; Keller, T.; Burkhard, R. A. Inform. Visual. 2006, 5, 167–174.

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4. Earl, B. L. J. Chem. Educ. 2007, 84, 1788–1789. 5. Ault, A. J. Chem. Educ. 2001, 78, 1347–1349. 6. Regis, A.; Albertazzi, P. G.; Roletto, E. J. Chem. Educ. 1996, 73, 1084–1088. 7. Robinson, W. R. J. Chem. Educ. 1999, 76, 1179–1180. 8. Nicoll, G.; Francisco, J. S.; Nakhleh, M. B. J. Chem. Educ. 2001, 78, 1111–1117. 9. Francisco, J. S.; Nakhleh, M. B.; Nurrenbern, S. C.; Miller, M. L. J. Chem. Educ. 2002, 79, 248–257. 10. Stensvold, M.; Wilson, J. T. J. Chem. Educ. 1992, 69, 230–232. 11. Zieneddine, A.; Abd-El-Khalick, F. Eur. J. Phys. 2001, 22, 501– 511. 12. Taber, K. S. Phys. Educ. 1994, 29, 276–281. 13. Ellis, G. W.; Rudnitsky, A.; Silverstein, B. Int. J. Eng. Educ. 2004, 20, 1012–1021. 14. Boschhuizen, R. Eur. J. Teach. Educ. 1988, 11, 177–184. 15. Nakhleh, M. B.; Krajcik, J. S. J. Res. Sci. Teach. 1993, 30, 1149– 1168. 16. Pendley, B. D.; Bretz, R. L.; Novak, J. D. J. Chem. Educ. 1994, 71, 9–15. 17. Shavelson, R. J.; Lang, H.; Lewin, B. On Concept Maps as Potential “Authentic” Assessments in Science; National Center for Research on Evaluation, Standards, and Student Testing, U.S. Department of Education: Washington, DC, 1993; Grant #R117G10027; ERIC #ED367691: http://www.eric.ed.gov:80/ERICDocs/data/ ericdocs2sql/content_storage_01/0000019b/80/15/5c/76.pdf (accessed Jan 2010). 18. MindNode is a freeware program for Mac OS X; the MindNode Pro upgrade allows for greater functionalities, such as cross-connections among branches, collapsing branches, and hyperlink support: http://www.mindnode.com/ (accessed Jan 2010). Cayra is a PC-only freeware program: http://download.cnet.com/Cayra/ 3000-2076_4-10777905.html (accessed Jan 2010). 19. McClure, J. R.; Sonak, B.; Suen, K. K. J. Res. Sci. Teach. 1999, 36, 475–492.

Supporting Information Available Full-sized, directly labeled versions of the six concept maps discussed in this paper. This material is available via the Internet at http://pubs.acs.org.


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Using Concept Maps To Teach a Nanotechnology Survey Short Course

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