Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Feature Using Animation in Forensic Pathology and Science Education Gary Fisk, PhD (Department of Psychology and Sociology, Georgia Southwestern State University, Americus, GA) DOI: 10.1309/LM2MP23DKGWWCCPJ labmedicine.com October 2008 j Volume 39 Number 10 j LABMEDICINE 587 A Feature nimated educational materials can provide significant advantages to teachers in the sciences. Many scientific topics, such as the cardiovascular system, have a visual-spatial component that can be naturally expressed with animations of scientific phenomena. The instructional benefits of animated biological examples have also led to increased use of animations in the courtroom, particularly in cases that involve medical evidence. Animations can help forensic pathologists communicate complex medical evidence to lay juries in a straightforward and accessible manner. Animations can also be useful for evaluating the likelihood of different scenarios that may have occurred during a crime. The present article explores the uses of animation in forensic pathology and science education. First, the use of animation as a tool for teaching juries and forensic investigation is covered. Next, the research evidence for the use of animations as educational supplements is reviewed. The article concludes with suggestions for maximizing the effectiveness of animations as instructional aids. The Use of Animations in Forensic Pathology Forensic experts distinguish between three forms of animation. The term “animation” is usually used to refer to dynamic illustrations, like those that might be used as a teaching aid.1 The term “scientific animation” is reserved for animations in which the motion is governed by scientific principles rather than an artist’s creative vision. The controlling principles that govern these animations are the laws of physics and realistic models of the human body, such as the positions of joints. Scientific animations in forensics may also include empirical data from the body or the crime scene. Scientific animations can, accordingly, be thought of as a form of three-dimensional data visualization. The third form of animation, “simulation,” is a scientific animation used specifically for prediction purposes.1 An important goal of forensic pathology is to instruct juries, which are typically composed of nonexperts, in the details of medical and scientific evidence that occurred during a crime. Animations can be helpful in courtroom settings for teaching the jury about the technically complex details of the case (Figure 1A, left). The use of medical animations in the courtroom has the greatest benefit for people with little background in biology or medicine. The members of the jury do not need to become experts in order to visualize and appreciate the details of the case being considered. In addition to jury instruction, forensic applications of animation can also include scientific animations that are closely based upon biological evidence from the victim and physical evidence from the crime scene (Figure 1A, right). The physical data can be digitized using capture techniques similar to the techniques used to make animated characters for movies (eg, the character Gollum from The Lord of the Rings) or video games (eg, John Madden Football). The data are modeled in a computer system based on physics, realistic biological models of the human body (eg, joint range of motion), and evidence from the crime scene. The resulting models can be animated so that the biological and physical objects involved in the crime interact. The scene can also be viewed from any number of perspectives. This approach has been successfully employed to create computer models of automobile accidents, particularly in regard to how the vehicle came into contact with the victim2,3 (Figure 1B). 588 LABMEDICINE jj Volume 39 Number 10 jj October 2008 Computer-based modeling of forensic data has a number of additional advantages.3 The electronic data can also be shared more easily between experts than physical evidence. Furthermore, the blood and other unappealing aspects of the injury can be removed for the jury, which might help the jury focus on the most important factors in the case and make evidence more admissible in court.1 The data from the physical evidence can also be easily stored on computers, which aids in conserving evidence.2 Animation and computer modeling of forensic data can also be used to help investigators draw conclusions about the events that occurred at the crime scene. One important application is matching crime scene evidence to biological evidence from the victim, with the goal of identifying perpetrators. Several studies have used this approach to match bite marks,4 tire tracks,5 and shoe treads3 to biological imprints left on the victim. Matching techniques have also been used to match the point of impact in car accidents2,3 and gunshot wounds6 (Figures 1A, left and 1B). A second important forensic application of animation is to test hypotheses about how an injury might have occurred. For example, March and colleagues1 employed computer-based models to test hypotheses about a suicide case in which the wrist was slashed and the heart was punctured. Based on computer models, they were able to determine that the stab wound to the chest would have been impossible to make with a utility knife, thereby ruling out one potential cause of death. Similar approaches have been used to determine the feasibility of self-inflicted gunshot wounds.7 The position of the gun, characteristics of the injury, and potential joint configurations can be modeled to determine whether or not a gunshot wound may have been self-inflicted. In sum, the use of animation and computer-based models to test forensic hypotheses is essentially a scientific approach to interpreting a crime. Hypotheses about the cause of death can be generated, and then computer models derived from empirical evidence can be tested to determine how likely each event might have been. The computer model can determine that some events might be physically impossible, which enables these impossible scenarios to be ruled out.7 The Use of Animation in Science Education Animation offers science instructors a tool for illustrating how a system changes over time. Instructors of upper-level biology students and medical students have typically reported improved educational outcomes when using animations as instructional aids. Animated materials have been used successfully to teach complex topics in cell biology,8,9 histology,10 and surgery.11-13 Several reviews of the educational psychology studies on animations show that animated materials can be effective teaching tools, but a number of studies have failed to demonstrate improved educational outcomes when animations are used.14-17 This literature suggests that a number of conditions must be met in order for animations to improve the learning process. The most common reason for using animation is to increase student interest in the subject material.18 The presence of motion in a display makes an illustration more dynamic, which may, in turn, increase intrinsic interest in the topic.19 Furthermore, today’s students have been raised in an environment rich in videos and visual stimulation. As a result, animated demonstrations of scientific topics may be more familiar and engaging for younger viewers. It is important to note, however, that there are distinct limits to the benefits gained by adding motion to an animated display. Excessive motion and realism can be distracting, which could interfere with learning.20 labmedicine.com Feature Animations are often used to make a presentation more dynamic. However, it is important to note that animations are only effective teaching tools when they are closely tied to the educational objectives that the teacher is seeking to accomplish.17 Animations can be dynamic and have impact, yet fail to improve student learning. For example, animated characters, such as cartoons, may not be very useful for education, even if they are dynamic and interactive. Older versions of Microsoft Office contained an animated character named “Clippit” or “Mr. Clippy” who was designed to help people effectively use their software. Although Mr. Clippy was a state-of-the-art interactive animation, this feature was widely disliked, possibly due to Mr. Clippy’s poor social skills.21 Educational research has sometimes produced results similar to the failed Mr. Clippy. Mayer, Dow, and Mayer22 used an animated character named “Dr. Phyz” to narrate an instructional animation on electric motors. The comparison of groups who learned the material with and without Dr. Phyz’s image failed to show that the presence of Dr. Phyz’s picture on the computer screen contributed to the learning process. In short, adding animation did not facilitate instruction under these conditions, even though the presence of Dr. Phyz was intended to engage and direct student attention. Thus, only animations that are closely aligned to instructional goals are likely to be effective teaching tools. In general, Rieber17 suggests that educators should “resist incorporating special effects, like animation, when no rationale exists.” The effectiveness of animation may depend, to some degree, on student abilities. Students who have a low degree of prior knowledge about a topic may benefit more from illustrated instructional materials than students who have a higher degree of prior knowledge.23 Furthermore, the effectiveness of animation may depend upon learning objectives. Dwyer and Dwyer24 found that the greatest educational benefits of animation were achieved when the students were given background information prior to viewing the animation. This information prepared them for viewing the animation, thereby helping the students to comprehend the animation. The benefits of animation may also vary depending upon student visual-spatial skills, with people who have lower abilities benefiting more from animation.25 Koroghlanian and Klein,26 A B Figure 1_Examples of forensic animation from the Virtopsy system. (A) Left: A 3-dimensional model of a shooting victim created from CT scan data. The blue figure is an anatomically correct, computer-generated model based on the bone structure. Right: A reconstruction of a shooting scene based on empirical evidence from the crime scene, such as damage from the skull and bed frame. (B) A 3-dimensional reconstruction of a traffic accident. All of the data in this reconstruction was derived from the bone structure of the victim and evidence from the accident scene. labmedicine.com October 2008 j Volume 39 Number 10 j LABMEDICINE 589 Feature Examples from Flix Productions. Examples from Animated Biomedical Productions. for example, divided students into low spatial ability and high spatial ability groups based on a spatial cognition task (internally visualized paper folding). They found that the students in the lower spatial ability group were more likely to report that the animation helped motivation and concentration on the learning task than the students in the high spatial ability group. However, the overall differences in learning outcomes were not different between the high and low spatial ability groups in this study. Animated teaching materials are the most effective when accompanied with a narrative that guides the viewers’ attention and explains the key events occurring in the animation. Several studies indicate that pairing animation with narration is more effective than having narration alone or animation with text.22,27-29 This effect is generally attributed to dual-coding theory,30 which proposes that learning is a process of forming connections between verbal and visual representations of the information. The cognitive representations are enhanced when complementary information is presented to both the verbal and visual modalities at the same time. Dual coding theory also suggests that placing written text beside animations might be counterproductive given that both the text and the visual images must be simultaneously processed by the visual system. It is important to acknowledge that animated instructional materials can occasionally introduce problems. Students may unintentionally learn misconceptions about the subject material from the animated illustrations.18 For example, some of the stu590 LABMEDICINE j Volume 39 Number 10 j October 2008 dents in one study who viewed animations about the diffusion of molecules in solution learned incorrect ideas about molecular motion from the simplified nature of the animation.31 It is important to point out, however, that only a small number of students in this study experienced this problem. Misleading information can easily sneak into instructional animations because the software does not contain any physical constraints based upon reality. The creation of educational animations must be done with caution to avoid misinformation that might be inadvertently learned. In summary, the educational studies on the use of animations in teaching indicate that animations can be an effective teaching tool provided that a number of conditions are met. The overall research findings clearly show that animations are not a panacea that will turn boring, poorly organized lectures into dynamic learning experiences. Animated instructional materials need to be carefully constructed and deployed in a way that meets specific educational needs in order to achieve maximum effectiveness. Using Animations as Instructional Aids The first step in using animations to enhance teaching is to examine how the animations will support the educational objectives (Table 1A). The animations must go beyond a simple “wow” response to a focus on delivering pedagogically sound learning experiences. The instructor must consider how the animation will illustrate the key points of the topic and visually reinforce concepts learned from the textbook or lecture. Park and Hopkins suggest that animations are the most effective when the certain instructional roles and conditions are met (Table 1B).16 These roles include guiding attention and aiding students in building mental representations of physical objects. Conditions for using animations include demonstrations of sequential actions and simulations of complex behaviors. Animations can also serve illustration purposes and are particularly valuable for teaching about anatomical structures that might not be readily visible to the naked eye. The second step is to consider the capabilities of the student audience and the role that the animation will play in their educational experience. There is at least some evidence that students who have lower prior knowledge of the topic will benefit more from animations than students with more knowledge. This suggests that animations might be most beneficial for high schools students, lay people in a jury, or lower-level college students. At the same time, however, individuals who have higher degrees of prior knowledge might potentially benefit from scientific animations if labmedicine.com Feature Table 1A_Steps for Implementing Animations in Educational Settings Step Objective 1 2 3 4 5 Identify educational objectives that the animation must support. Determine the capabilities of the audience that will see the animation. Locate or create animations that will meet both the educational objectives and the capabilities of the audience. Presentation: Prepare the audience for the animation by giving them sufficient knowledge to comprehend the animation. During the presentation, narration should also be provided to point out important features and explain the events. Evaluate the instructional effectiveness of the animation. Table 1B_Recommended Uses of Animations from Park and Hopkins16 Instructional Roles Instructional Conditions As an attention guide As an aid for illustration As a representation of domain knowledge As a device model for forming a mental image As a visual analogy or reasoning anchor for understanding abstract and symbolic concepts or processes For demonstrating sequential actions in a procedural task For simulating causal models of complex system behaviors For visually manifesting invisible system functions and behaviors For illustrating a task difficult to describe verbally For providing a visually motional cue, analogy, or guidance For obtaining attention focused on specific tasks or presentation displays these are being used as interactive visualizations of complex threethree-dimensional model building. In sum, creating animations dimensional data, as suggested by the medical literature and the is a major undertaking, but it can be a rewarding way to achieve forensic uses of animation. unique educational objectives. The third step is to find or create the animations that meet The fourth step is to present the animation to the target the educational objectives. Many science textbooks for understudent audience in an effective manner. The research evidence graduate students have multimedia supplements that are available suggests that students benefit more from animations when they for free upon adoption of the textbook. These supplements can be obtained by contacting the textbook publisher’s sales representative. There are also a number of Web sites that contain animations that can be freely downloaded by anyone. Several examples are shown in Table 2. Animations can also be created by anyone who has the proper equipment and a moderately high degree of computer skills. The chief downside to creating animations is that the Examples from Nucleus Medical Art. process is difficult, expensive, and time-consuming. The Table 2_Links to Animation Examples standard for two-dimensional animation on the Web is Adobe Forensic/Medicolegal Examples Flash (formerly Macromedia Description URL Flash), which is typically created with Flash Creative Suite 3 Virtopsy—Forensic Animation http://www.virtopsy.com/ (CS3). More sophisticated softFlix Productions http://www.medflix.com/movie.html Animated Biomedical Productions http://www.medical-animations.com/gallery.php ware applications are available Medical Legal Art http://medicolegalart.com/animation.html for creating three-dimensional Nucleus Medical Art http://www.nucleusinc.com/ animated models. Tom GuthGhost Productions http://www.ghostproductions.com/ rie, of Flix Productions (www. medflix.com), uses 3ds-Max as Teaching Examples his primary animation software for realistic, three-dimensional Description URL animations. The use of scientific Virtual Cell Animation Collection http://vcell.ndsu.nodak.edu/animations/ animations in forensic pathology Neuroscience and sensory animations created by Gary Fisk http://www.garyfisk.com/anim/index.html is the most demanding of all, Cell biology animations created by Donald Slish http://faculty.plattsburgh.edu/donald.slish/animations.html as it requires significant investDNA animations from the DNA Learning Center http://www.dnalc.org/ddnalc/resources/animations.html ment in data acquisition tools, Cell biology animations from Cells Alive! http://www.cellsalive.com/ data collection processes, and labmedicine.com October 2008 j Volume 39 Number 10 j LABMEDICINE 591 Feature have some advanced preparation, such as basic information about the topic, prior to seeing the animations. This prior knowledge appears to help students properly understand and interpret the information presented in the animation. During the presentation, it is also important that narration should be used to explain the events occurring in the animation. Providing narration should help to direct student attention to the most important features of the animated display. Simultaneous presentation of the animated visual information and narrative information should also help provide optimal learning conditions according to dual-coding theory. The final step would be to evaluate the effectiveness of the animated supplements. For example, the students might be able to volunteer their opinions about the animations. Teachers should also be on the lookout for evidence that the animations are entertaining, but not educational. There is also the possibility that the students might inadvertently learn misconceptions or pay attention to irrelevant parts of the animation. If these patterns are noted, either corrective steps can be taken or the use of the animation should be discontinued. Conclusion Animated models offer great potential for improved instruction in forensic pathology and science education, particularly in regard to the visualization of complex physical structures. Although this approach is relatively new, it is already beginning to have an impact in the courtroom and in training of future scientists and laboratory technicians. It is likely that the future of forensic pathology will see much greater employment of animated data visualization and animated models as tools for understanding and communicating biological information. LM Acknowledgments: We thank the following individuals and medicolegal animation firms who gave permission for the artwork used in this article: Tom Guthrie (Flix Productions Biomedical Animation), Sue Snape (Nucleus Medical Art,), and Des Sloan (Animated Biomedical Productions). We also thank Michael Thali (University Forensic Institute—Bern) for contributing an example of scientific animation in forensic pathology. Finally, we thank Ellen Cotter for providing feedback on this manuscript. 1. March J, Schofield D, Evison M, et al. Three-dimensional computer visualization of forensic pathology data. Amer J Forensic Med Pathol. 2004;25:60–70. 2. Buck U, Naether S, Braun M, et al. Application of 3D documentation and geometric reconstruction methods in traffic accident analysis: With high resolution surface scanning, radiological MSCT/MRI scanning, and real data based animation. Forensic Sci Int. 2007;170:20–28. 3. Thali MJ, Braun M, Buck U, et al. VIRTOPSY-Scientific documentation, reconstruction, and animation in forensic: Individual and real 3D data based geometric approach including optical body/object surface and radiological CT/MRI scanning. J Forensi Sci. 2005;50:428–442. 4. Thali MJ, Braun M, Markwalder TH, et al. Bite mark documentation and analysis: The forensic 3D/CAD supported photogrammetry approach. Forensic Sci Int. 2003;135:115–121. 5. Thali MJ, Braun M, Brüschweiler W, et al. Matching tire track on the head using forensic photogrammetry. Forensic Sci Int. 2000;113:281–87. 6. Thali MJ, Braun M, Wirth J, et al. 3D surface and body documentation in forensic medicine: 3-D/CAD photogrammetry merged with 3D radiological scanning. J Forensi Sci. 2003;48:1356–1365. 7. Subke J, Haase S, Wehner HD, et al. Computer aided shot reconstructions by means of individualized animated three-dimensional victim models. Forensic Sci Int. 2002;125:245–249. 8. McClean P, Johnson C, Rogers R, et al. Molecular and cellular biology animations: Development and impact on student learning. Cell Biol Educ. 2005;4:169–179. 9. Thatcher JD. Computer animation and improved student comprehension of basic science concepts. J Amer Osteopath Assoc. 2006;106:9–14. 10. Brisbourne MA, Chin SS, Melnyk E, et al. Using web-based animations to teach histology. Anat Rec. 2002;269:11–19. 592 LABMEDICINE j Volume 39 Number 10 j October 2008 11. Glittenberg C, Binder S. Using 3D computer simulations to enhance ophtalmic training. Ophthalmic Physiol Opt. 2006;26:40–49. 12. Henderson BA, Ali R. Teaching and assessing competence in cataract surgery. Curr Opin Ophthalmol. 2007;18:27–31. 13. Kobayahsi M, Nakajima T, Mori A, et al. Three-dimesional computer graphics for surgical procedure learning: Web three-dimensional application for cleft lip repair. Cleft Palate Craniofac J. 2006;43:266–271. 14. Anglin GJ, Vaez H, Cunningham KL. Visual representations and learning: The role of static and animated graphics. In: Jonassen DH, editor. Handbook of Research on Educational Communications and Technology. 2nd ed. Bloomington, IN: The Association for Educational Communication and Technology; 2004: 865–916. 15. Lin H, Ching Y, Ke F, et al. Effectiveness of various enhancement strategies to complement animated instruction: A meta-analytic assessment. J Educ Technol Sys. 2006;35:215–237. 16. Park OC, Hopkins R. Instructional conditions for using dynamic visual displays: A review. Instruct Sci. 1993;21:427–449. 17. Rieber LP. Animation in computer-based instruction. Educ Tech Res Devel. 1990;38:77–86. 18. Rieber LP. Animation, incidental learning, and continuing motivation. J Educ Psychol. 1991;83:318–328. 19. Hall DW. Computer-based animations in large-enrollment lectures: Visual reinforcement of biological concepts. J College Sci Teach. 1996;25:421–425. 20. Owens R, Dwyer F. The effect of varied cueing strategies in complementing animated visual imagery in facilitating achievement of different educational objectives. Int J Instruct Media. 2005;32:373–384. 21. Whitworth B. Polite computing. Behav Inf Technol. 2005;24:353–363. 22. Mayer RE, Dow GT, Mayer S. Multimedia learning in an interactive selfexplaining environment: What works in the design of agent-based microworlds? J Educ Psychol. 2003;95:806–812. 23. Mayer RE, Gallini JK. When is an illustration worth ten thousand words? J Educ Psychol. 1990;82:715–726. 24. Dwyer F, Dwyer C. Effect of cognitive load and animation on student achievement. Int J Instruct Media. 2006;33:379–388. 25. Hays TA. Spatial abilities and the effects of computer animation on short-term and long-term comprehension. J Educ Comput Res. 1996;14:135–155. 26. Koroghlanian C, Klein JD. The effect of audio and animation in multimedia instruction. J Educ Multimedia Hypermedia. 2004;13:23–46. 27. Dunsworth Q, Atkinson RK. Fostering multimedia learning of science: Exploring the role of an animated agent’s image. Comp Educ. 2007;49:677–690. 28. Mayer RE, Anderson RB. The instructive animation: Helping students build connections between words and pictures in multimedia learning. J Educ Psychol. 1992;84:444–452. 29. Mayer RE, Moreno R. A split-attention effect in multimedia learning: Evidence for dual processing systems in working memory. J Educ Psychol. 1998;90:312–320. 30. Clark RE, Paivio A. Dual coding theory and education. Educ Psych Rev. 1991;3:149–210. 31. Sanger MJ, Brecheisen DM, Hynek BM. Can computer animations affect college biology students’ conceptions about diffusion and osmosis? Amer Biol Teach. 2001;63:104–109. labmedicine.com