Nanotechnology is “the understanding and control of matter at dimensions between approximately 1 and 100 nanometers, where unique phenomena enable novel applications. Encompassing nanoscale science, engineering, and technology, nanotechnology involves imaging, measuring, modeling, and manipulating matter at this length scale” (NNI, 2009). The National Center for Learning and Teaching in Nanoscale Science and Engineering (NCLT) and the National Science Teachers Association (NSTA) discuss the “big ideas” of nanotechnology education. The concept of size and scale is one of these “big ideas” (Stevens, Sutherland, Krajcik, 2009) .
NCN Conducted Research
Based on analysis of students’ solutions to the Spring 2013 design project, the research team developed the following framework for size and scale concepts. These categories correspond to some categories already developed in relevant literature (Delgado, Stevens, Shin, Yunker, & Krajcik, 2007; Light, Swarat, Park, Drane, Tevaarwerk, & Mason, 2007; Magana, Brophy, & Bryan, 2012) and propose some new ones (Rodgers, Kong, Diefes-Dux, & Madhavan, 2014).
Size (Qualitative)
Relational: Comparisons of objects that only state smaller or bigger (ordering of objects) without any quantification. (e.g. fly > blood cell > virus > DNA > nanoparticle)
Proportional: Two objects differences in size compared through an analogy to two other objects’ size differentiation. (e.g. If a nanoparticle was the size of a football, a red blood cell would be the size of the football field.)
Scale (Quantitative)
Absolute: Evaluates objects by giving a specific measurement; both numeric value and scale. (e.g. width of DNA = 2.5 nm)
Categorical: Evaluates objects by categorizing the appropriate scale to measure it. (e.g. DNA = nanoscale; fly = macroscale)
Relational: Comparisons of numeric values that only state smaller or bigger (ordering of values) without any qualification.(e.g. 5,000,000 nm > 3 mm > 0.00007 cm)
Proportional: Objects’ size differentiation compared using multiplication (number of times smaller or bigger). (e.g. a red blood cell is 10,000 times bigger than a nanoparticle)
Below is an image of types of representations of size and scale that appeared in students’ solutions (n = 30 teams)
References:
Rodgers, K.J., Kong, Y., Diefes-Dux, H.A., & Madhavan, K. (2014). First-year engineering students’ communication of nanotechnology size and scale in a design challenge. Proceedings of the 121st ASEE Annual Conference and Exposition, Indianapolis, IN.
Stevens, S.Y., Sutherland, L.M., & Krajcik, J.S. (2009). The big ideas of nanoscale science & engineering: A guidebook for secondary teachers, National Science Teachers Association, United States of America, pp. 5-72.
NNI (2009). Nanotechnology: Big things from a tiny world. The National Nanotechnology Initiative http://www.nano.gov/html/society/Education.html
Delgado, C., Stevens, S. Y., Shin, N., Yunker, M., & Krajcik, J. (2007). The development of students’ conceptions of size. In annual meeting of the National Association for Research in Science Teaching, New Orleans.
Light, G., Swarat, S., Park, E. J., Drane, D., Tevaarwerk, E., & Mason, T. (2007). Understanding undergraduate students’ conceptions of a core nanoscience concept: Size and scale. In Proceedings of the First International Conference on Research in Engineering Education.
Magana, A. J., Brophy, S. P., & Bryan, L. A. (2012). An Integrated Knowledge Framework to Characterize and Scaffold Size and Scale Cognition (FS2C). International Journal of Science Education, 34, 2181-2203.