WHAT ARE WE SUPPOSED TO SEE?
VISUAL PERCEPTION OF SMALL AQUATIC ANIMALS BY NON-SCIENCE MAJORS AND BIOLOGY
GRADUATE STUDENTS; COMPARISONS, CORRELATIONS AND IMPLICATIONS.
2001 Annual International
Conference of the Association for the Education of Teachers of Science. Costa
Mesa, California. January 2001. Robert Day, The Ohio State
University.
Day.3@osu.edu
This study aims to evaluate novice biologists' ability to visually perceive small living specimens in artificial ecosystems and compares the visual ability of novices with that of experienced field biologists. It also uses observations of informant behavior and structured interviews to identify attitudes, educational factors and past experiences that might correlate with visual ability. Some specific correlations are suggested and explanations for observed patterns are explored. The study is part of an ongoing investigation into the role of "biological visual literacy" in life-science education. Biological visual literacy is defined here as the sum of an observer's ability to visually search for, recognize, perceive and subsequently interpret biologically relevant information. The investigation concentrates on how this skill influences students' understandings of biodiversity. Biological visual literacy is essential for most life-science professions and is also desirable in average citizens because it promotes environmental awareness. It is unlikely that non-science majors will value biodiversity if they are incapable of visually perceiving the living things around them. By examining and documenting the visual difficulties of novice biologists and by identifying the most useful educational experiences of "expert" observers, we hope this study will yield information useful to the improvement of biology instruction at Ohio State and elsewhere. The presentation will summarize the data gathered so far and use short video clips to illustrate emerging patterns.
The investigation was inspired by casual observations of learning difficulties in first and second year Zoology students at The Ohio State University's Department of Evolution, Ecology and Organismal Biology. During a curriculum review of an introductory animal diversity class, instructors came to realize that the traditional approach to teaching taxonomy (using rote memorization of preserved specimens in jars) did little to inspire students and almost nothing to help them develop useful field or microscopic observation skills. When asked to find and identify actual living things, we found that traditionally trained students were often unable to do so because they had difficulty interpreting shapes, structures, textures and lighting conditions that they do not usually experience when observing an isolated specimen in a jar. The problem is exacerbated by modern, generally urban American culture, since today's young people rarely have the opportunity to spend time observing nature and constructing a "visual vocabulary" of living things. Negative societal messages about biodiversity may also contribute to an unwillingness to look closely at small organisms, which popular culture generally depicts as "dirty" or "gross". In some specific examples of observational difficulties, students seemed unable to see indicated living specimens at all or were unable to match a picture of a specimen with its real world counterpart. Students would draw air bubbles instead of cells, shrimp instead of crabs or algae instead of animals. Students stated that they sometimes felt extremely frustrated because, from their perspective, it seemed as if they were being asked to observe specimens that simply did not exist. Some complained that the microscope must be faulty because they could not see anything that looked like the line-graphic diagrams in their books. In contrast, experienced instructors usually had no trouble finding and identifying living specimens, even those they had never seen before. In other examples of observational difficulties, students were distracted or misdirected by visual information not relevant to the task at hand or were unable to differentiate living organisms from their background. Others had difficulty "scaling down" their observational techniques to look for specimens smaller than the household objects they usually encounter or were unable to systematically search a three dimensional space by progressively focusing through it. When novice students did finally locate a living specimen, they tended to see it as a two-dimensional isolated whole rather than perceiving it as a three-dimensional collection of separately identifiable parts that may have equivalents in other specimens.
Novices also found it difficult to interpret what they saw as a specific example from which they could infer the appearance of a general set, or a new example of something that belonged to a set they have already seen. Similarly, students also had problems developing a realistic idea of just how similar two living things must look in order to be classified as closely related or the same. The illumination of these learning difficulties led to the development of a new lab curriculum for Ohio State's introductory animal diversity class that emphasizes hands-on observational exercises, abundant images of "real" biological phenomena, and real-time videomicroscopy of live organisms housed in artificial ecosystems. The details of this approach are given elsewhere. (Day, 1996)
In order to document these difficulties I developed a simple instrument intended to examine informants' ability to see small living things. The sample population for this study comprises volunteers drawn from an introductory biology class for non-majors and graduate student volunteers from life science and non-science fields. Informants were asked to observe living things in two small, artificial habitats. The first system consists of a one-liter, water-filled jar containing about thirteen small, but macroscopic species (ranging in size from about 0.5mm to 5mm). The second habitat was a ten-gallon terrarium housing stable populations of giant Madagascan cockroaches, a species of mite and a small species of beetle. Informants were also asked to observe a third container filled with pure water to make sure they were not "seeing" any non-existent species. Informants were asked to point out all the living things they could see. They were not asked to identify them, since this experiment was intended as an analysis of visual perception only, not a test of taxonomic knowledge. When accurate identifications were offered, they were noted as a sign of the informant's level of overall background knowledge. Informants described what they saw and any observational strategies that they employed. All sessions were videotaped for later analysis. After the observational phase of the study was complete, informants were interviewed in order to assess past educational experiences and attitudes towards living things.
Initial findings indicate that informants vary in their ability to visually perceive small living organisms in artificial ecosystems and that novice biologists generally do not see specimens as easily as experienced biologists. Visual ability appears to correlate with past educational experiences specifically designed to enhance students' ability to observe living things and, to a lesser extent, with outdoor activities in general. Informant indications of empathy for, or positive feelings about living things and the environment may also correlate somewhat with visual ability. Detailed and technically accurate knowledge of the mechanics of ecosystems does not seem to correlate with observational ability, indeed students with misconceptions about ecological mechanics do not necessarily seem to be at a disadvantage when it comes to their ability to see living things under the conditions of this study.
Since this study suggests that novice biologists do not visually perceive the same thing as each other, or as their instructors, it should not be assumed that students "see" what the instructor thinks they do. What students visually perceive appears to be influenced by past knowledge and experience. This is old news to specialists in the field of psychology, who have written much on the theory laden nature of what we think we see (for a review see Bruce et al, 1996). Unfortunately, biology teachers rarely recognize this as a barrier to learning. Analysis of the video data suggests that adopting an instructional strategy analogous to the conceptual change model of Posner (1982) may be one way to prompt students to re-evaluate the accuracy of the mental image they initially form. The data also suggest that it may be beneficial to expose K through twelfth grade students to fieldwork and other exercises specifically designed to develop their ability to see living things, since childhood involvement with these kinds of activities seem to correlate with student's observational abilities at the college level. Conversely, Gardner (1997) has suggested that "naturalistic intelligence" is an inherent quality of some individuals. If he is correct, we might expect to encounter some individuals who would find the tasks evaluated in this study inherently easy, even without any relevant past experience. More work is needed to determine the extent to which biological visual literacy is a property that can actually be improved using appropriate instructional techniques, or whether some individuals may have inherent visual abilities that are largely innate.
References
Bruce, V. Green, P. R. & Georgeson, M. A. (1996). Visual perception: Physiology, Psychology and Ecology (3rd ed.). Hove, East Sussex.
Day, R. (1996) Bringing Undergraduate Biology to Life with Model Ecosystems and Imaging Technology. Proceedings of the Annual Conference of The American Zoo and Aquarium Association. New Orleans, LA. Available at: https://www.angelfire.com/ri/skibizniz/papers.html
Gardner, Howard.(1997) Are There Additional Intelligences? The Case for Naturalist, Spiritual, and Existential Intelligences. In J. Kane (Ed.), Education, Information, and Transformation. Englewood Cliffs, NJ: Prentice-Hall.
Posner, G.J., Strike, K.A., Gertzog W.A. (1982) Accommodation of a scientific conception: Toward a theory of conceptual change. Science Education. 66, 211-227
