Interactive learning Collaborative moelling of the vascular system esigning an evaluating a new learning metho for seconary stuents Marion Haugwitz an Angela Sanmann Biology Eucation, University of Duisburg-Essen, Germany Unerstaning biological structures an functions is often ifficult because of their complexity an micro-structure. For example, the vascular system is a complex an only partly visible system. Constructing moels to better unerstan biological functions is seen as a suitable learning metho. Moels function as simplifie versions of real objects an concentrate on special features of those to facilitate learning. Because of the complexity of the vascular system, moels can be implemente as beneficial teaching ais. Learning with moels is also an effective form in combination with collaborative learning. This paper introuces three simplifie heart an bloo vessel moels. They were esigne for collaborative learning. The moels were implemente in a stuy with 7th grae stuents (13 years ol). Results of a paper-pencil evaluation show that collaboratively learning with moels of the heart an the bloo vessels was interesting for stuents. Furthermore, stuents gaine better unerstaning an achieve higher test scores. Keywors: heart, moel, collaborative learning Moels in Biology Moels are seen as a key tool in thinking an working scientifically as they enhance investigation, unerstaning an communication (Harrison an Treagust, 2000). In teaching biology, moels are use to realistically emonstrate biological processes, systems or objects as those are often too complex, large or small to be irectly observe (Rotbain, 2006). As such, they are simplifie representations of originals (Gilbert an Osborne, 1980). In contrast to real objects, moels have the potential to isplay only relevant etails an thereby help explain complicate functions. They are consiere important learning an teaching ais (Harrison an Treagust, 2000), an are implemente specifically when complex mechanisms nee to be clarifie. The circulatory system with its complex an multiple levels of organization is ifficult to represent without simplification an therefore har to unerstan for stuents (Buckley, 2000; see also Tunnicliffe an Reiss, 2000). As human circulatory processes are very complex, learning with moels which o not inclue every etail of the original may foster interest an greater unerstaning. Lee (2004), for example, use a moel in aition to working with a pig s heart to further enhance stuents unerstaning of a coronary heart isease. Collaborative Learning Working in groups promotes collaborative learning (Chin, 2004) an offers several avantages over iniviual learning. Through iscussing newly introuce concepts, stuents can integrate iniviual knowlege with collective knowlege. Empirical evience shows that stuents unerstan concepts better if they communicate them while learning (Duit an Treagust, 1998; Lemke, 1990; Palincsar, Anerson an Davi, 1993). Seymour an Paberg (1975) showe that this approach oes not only foster improve communication an problem solving skills, but also achievement. Clearly, the combination of collaborative learning an learning with moels provies many avantages. From a practical view, builing complex moels is easier in groups. Furthermore, a collaborative learning environment offers the avantages to obtain ifferent points of views an to iscuss ifferent aspects of the moels. Regaring classroom management, collaborative work reuces the amount of materials require for each stuent. Learning Kits Three learning kits on the function of the heart an bloo vessels are introuce below. The kits can be use alone or in sequential combination. The tasks are about how the heart works, about the pulse an the veins. 136 JBE Vol 44 No 3 Summer 2010
Moelling of the vascular system Haugwitz an Sanmann The kits contain all learning materials necessary for the moels construction. They inclue two types of cars: those introucing the assignments (Problem Cars), an those covering content an structural assistance (Information Cars). The materials utilize are common laboratory or househol items. While learning with the kits, stuents are aske to verify a hypothesis, plan an construct the moel, an iscuss the result. Eucation through learning kits iffers from a simple execution of an assignment. The stuents must become actively engage in the matter, iscuss an reflect upon their ieas, an cooperatively problemsolve by builing the moel. The assignments in the learning kits are contextualize with realistic situations (such as physical function uring sports, or after an accient) in orer to enhance interest an participation in the task. The learning kits can be implemente in regular classroom instruction. Teachers may assist stuents with content or technical an practical information. To assess progress, stuents can be aske to protocol their hypotheses an learning steps. Finally, results shoul be reviewe in a classroom iscussion. Kit 1: How the Heart Works The Problem Car in this learning kit is shown in Figure 1. Stuents are aske to buil a moel that illustrates the heart function. They are introuce to the topic by a story about a girl an her granfather, who is no longer Problem Car Ann woul like to race her 69-year-ol granpa. He refuses, arguing that his pump is too ol. Ann woners why the heart is also calle a pump. Answer her question using the material in the kit. Try to buil a moel of the heart s pump function while consiering the points below. 1. Fin a way to bring the flui from one glass to the other while taking note of what you observe. 2. What o the materials of your moel represent in your boy? Figure 1: Problem Car: The Heart as a Pump Information Car The heart is a muscular organ responsible for pumping bloo through the bloo vessels. The human heart has two ifferent types of valves which etermine the irection of bloo flow. semilunar valve aorta atrium Figure 2: Information Car: Anatomy of the Heart mitral valve heart chamber cross-section of heart able to race with her. The learning goal of the kit is to iscover how the heart works an learn that age ecreases the heart s ability. The Information Car (Figure 2) provies backgroun on the anatomy of the human heart. It explains the iniviual functions of the ifferent heart valves. To complete the assignment, stuents must use the material liste below, which is provie in the kit: a) 500 ml re-coloure water, b) 1 laboratory beaker, c) 1 marble, ) 1 funnel with a hole in the sie, e) 1 balloon, f) 1 rubber hose, g) 1 piece of tape, h) 1 piece of film, an i) 1 laboratory beaker. f g h i Figure 3: Moel of the Heart s Function The complete moel for self-irecte learning through learning kits is shown in Figure 3. It is a moifie version of the one esigne by the Department of Diactics of Physics at the Karl Franzens University of Graz (Anerwal, 1998) which was esigne to better unerstan the pressure create through the heart s function. To buil the moel shown in Figure 3, stuents must insert the marble into the funnel, put the rubber hose into the hole in its sie, an place the balloon over the funnels top. The film must be tape on the other en of the rubber hose. After completing these preparations, stuents have to push own on the balloon that will cause the liqui to rise into the funnel, whereas the marble prevents the water from streaming back into the glass. By continuing pressing on the balloon, the flui will finally flow from the funnel through the rubber hose into the other glass where the film at the en of the rubber hose keeps it from flowing back in. To buil the moel, stuents have to iscuss the ifferent possibilities of putting the materials together. For example, without the marble in the funnel, the moel oes not work because the flui always runs back e c b a JBE Vol 44 No 3 Summer 2010 137
Haugwitz an Sanmann Moelling of the vascular system own. Finally, stuents must think about the moel an what the materials represent in their boies. The following list gives insight into what the materials represent. a) Bloo, b) Atrium c) Mitral valve, ) Heart chamber, e) Heart muscle, f) Semilunar valve, g) Semilunar valve, h) Semilunar valve, i) Human boy. Kit 2: The Pulse (Arteries an Capillaries) The assignment in the learning kit about bloo vessels is provie on the Problem Car below (Figure 4). Stuents are aske to fin out in which bloo vessels one might fin a pulse. They are introuce to the topic by a story about a bicycle accient, as a result of which bloo pulses out of an injury. Problem Car John falls from the bicycle he is riing. He injures his wrist an bloo spurts in pulses from it. Think about why the bloo flows in pulses an not continuously, as is the case with other physical injuries. Using the materials provie, construct a moel showing in which bloo vessels the bloo flows in pulses an in which continuously. 1. Observe what you feel with the big hose if you press the pump bulb uner water. You can buil three ifferent moels with the given materials. Experiment an rationalise which works best, paying close attention to how the water flows. 2. What o the materials of your moel represent in your boy? Figure 4: Problem Car: Pulse in the Bloo Vessels Information Car With every heart beat, the heart pumps bloo through your boy. In some bloo vessels, there are pressure waves which can be felt; these are calle pulse. Arteries are bloo vessels that carry bloo away from the heart. Bloo flows from the heart to arteries, which narrow into capillaries. Capillaries are the smallest of a boy s bloo vessels. They are very thin an elastic. Figure 5: Information Car: Backgroun on Arteries an Capillaries The learning goal of this kit is to unerstan the ifferent anatomy an functions between arteries an capillaries. Furthermore, stuents shoul unerstan that injuries of arteries versus capillaries may result in varying, potentially serious consequences (Figure 5). The moel in the learning kit on bloo vessels is a combination an moification of two moels by Baer Figure 6: Moel of Pulse Function (1985) an Falkenhahn et al. (1981). In both moels, a rubber hose is connecte to a water tap. The tap is manipulate so that the water flows out in pulses. Stuents will iscover that the water flows regularly as the rubber tube gets thinner. In the Falkenhahn et al. (1981) moel, stuents install ifferent types of hose ens to compare them with each other. The actual moel provie here is moifie so that the water tap is replace by a squeezable pump bulb. This variation is more suitable for stuents an causes less flooing. The moel is shown in Figure 6. The kit contains: a) 1 squeezable pump bulb, b) 1 large rubber hose, c) 1 small rubber hose, ) 1 glass tube, e) 1 small rubber hose in combination with f) 1 thin glass tube. a b e f Problem Car Diana is going to a pop concert. Together with her friens, she waits in a crow to get into the concert hall. After several hours, their legs ache. This is because the transport of bloo from the legs is mae more ifficult by the long wait an inactive staning. Fin out why this is the case. Buil a moel that shows how the bloo returns from your legs to your heart. 1. How can you prouce pressure to bring the bloo back? 2. What o the materials of your moel represent in your boy? Figure 7: Problem Car: Bloo Transport through Veins Information Car The bloo pressure cause by the heart beat cannot be felt as a pulse in capillaries or veins. The bloo flows through them at a constant pace. Capillaries wien to become veins, which return bloo to the heart. Most veins have one-way flaps calle venous valves that prevent bloo from flowing back an pooling in the lower extremities as a result of gravity. Muscles wrappe aroun veins help maintain bloo flow to the heart. Figure 8: Information Car: Backgroun on Veins c 138 JBE Vol 44 No 3 Summer 2010
Moelling of the vascular system Haugwitz an Sanmann The kit also contains connectors to combine the materials with each other, as well as re-coloure water. Stuents must combine the pump bulb with the big hose. The pump simulates the heart an the big hose correspons to an artery. If the stuents compress the pump bulb, they can feel a pulse in the big rubber hose. Three possible aapters (c,, an e / f) can be teste sequentially to see which best simulates a capillary. If aapter c an are installe, the water flows through the capillary with a pulse. The solution for the capillary is the aapter that is both very elastic an very thin (e / f). Kit 3: Veins How oes the bloo return to your heart from your legs? This is the question stuents must answer with the thir moel. The Problem Car is shown in Figure 6, while the respective content information follows in Figure 7. The moel the stuents have to construct is base on Thiessen s heart moel (1979). Because of its configuration, it is more suitable to emonstrate the veins with two vein valves than the heart function so that it was moifie an chosen as a moel for the anatomy an function of the veins. The kit moel is shown in Figure 9 an is built using the materials liste below: a) 500 ml re-coloure water, b) 1 laboratory beaker, c) 1 small plastic tube, ) 4 aapters, e) 2 plastic tubes, f) 1 silicon tube, g) 1 laboratory beaker, h) 2 neeles, i) 2 pieces film. Furthermore, the kit contains connectors to combine the materials with each other. To bring the re flui from one glass to the other, stuents must squeeze the plastic tubes. This causes the e c b a Figure 9: Moel of Vein Function f g h i water to rise, while the pieces of film (affixe with neeles) prevent it from flowing back. Once finishe, the stuents shoul consier the moel an think about what the materials are equivalent to in their boies. The solution is provie below: a) Bloo, b) Boy, c) Capillary, ) No special function, e) Veins, f) No special function, g) Heart, h) Vein valve, i) Vein valve. Implementation an Evaluation The escribe learning kits have been assesse in a stuy with a pre- an post-test evaluation. The goal was to investigate whether stuents were intereste in learning with the kits an in the provie scenarios on the problem cars. Furthermore, the achievement level an the level of cooperation were measure. The stuy took place in grae seven in a seconary school in Essen, Germany. The stuy was realize as an out-of-school activity. The forty stuents who participate ha an average age of 12.4 years (SD = 0.55). The proportion of male/female participants was at exactly 50 %. Participation was unsolicite an with parental agreement, an the stuents were allowe to form their own groups which resulte in eleven groups of three to five stuents. Stuents who participate in the stuy attene five sessions: a pre-test session, a post-test session an three learning sessions in which the groups were engage with the three learning kits, one after the other. Before learning with the kits, stuents ha to complete a prior knowlege test consisting of several multiple choice questions concerning the content knowlege of the learning kits (example item: Which characteristic istinguishes veins? a) veins are very thin bloo vessels b) veins contain valves c) veins transport bloo away from the heart ) veins are muscles ). Each of the three learning sessions took place on a ifferent ay. Stuents ha 25 minutes to solve the given problems, i.e. with reference to the problem car they were aske to buil the require moel an answer the question what the materials in the moel represent in their boy. Directly after each learning session, stuents ha to fill out a questionnaire about situational interest as well as an achievement test with items referring to the learning task of the respective session. In aition, one week after the collaborative learning, each stuent ha to fill out an achievement test consisting of the same items as the prior knowlege test, as well as a questionnaire about their interest in the project (post-test). All achievement tests were multiple choice tests, an the questionnaires about situational interest consiste of two scales: interest in builing the moel (6 items, example item: I enjoye learning with the kit toay ) an the interest in the JBE Vol 44 No 3 Summer 2010 139
Haugwitz an Sanmann Moelling of the vascular system provie real-life scenarios (5 items, example item: I was intereste in the topic on the problem car ). Furthermore, stuents ha to answer four items about how well the collaboration within the group worke (example item: We supporte each other in our group ). All items were formulate using a 4-point Likert scale with higher values inicating higher interest or better cooperation. Table 1 shows the escriptive results of the interest in the learning kits an the achievement scores. The results of the evaluation stuy show that stuent interest scores are all above average, at 2.5. This supports the iea that stuents were intereste in learning with the kits. Stuents reporte a high value for the scale of the interest in the project. This shows that stuents are highly intereste in the outof-school activity with a collaborative biological learning environment. In all three cases, the interest in the moel itself was higher than the interest in the problem. This might result because the moelling activity was a hanson activity while the realistic scenario was only escribe by text an pictures. Kit 1 ha the greatest appeal, an stuents achieve higher knowlege gain. Stuents felt collaboration was best with kit 2. This may be because builing moel 2 require greater stuent participation through clamping the materials. For the pre- an post-test comparison, a paire sample t-test was conucte with the prior knowlege an the post-test achievement (t(39) = 7.49, p <.001). The result shows that stuents profite significantly from learning with the kits. This means that stuents acquire biological knowlege of the human heart an the vascular system while collaboratively learning with the kits. Conclusion The learning kits were esigne to provie an opportunity to collaboratively learn the function of the heart, the cause of the pulse an the function of the veins through the construction of simplifie moels. Builing moels is one way to easily learn about complex processes by reucing the amount of information. Results of the evaluation show that this is true for the given content (function of the heart an the bloo vessels). Furthermore, finings inicate that learning with the presente learning kits is interesting for stuents. Builing these moels in small learning groups creates several avantages, such as the amount of material neee for the classroom can be reuce. Moreover, stuents can assist each other, while still benefiting from teacher support. The teacher can also point out the limitations of moels an expan on the topic through further textbook-specific instruction. The fining that stuents engage in learning activities besies regular class, report high interest, an gain knowlege shoul encourage biology eucators to implement collaborative hans-on activities in eucation. 140 JBE Vol 44 No 3 Summer 2010 Table1: Descriptive Results: Mean Values (Stanar Deviation) Interest in Interest in Achievement Interest in the Moel the Problem Collaboration Score [%] the Project Pre-test 51 (11) Kit 1 3.31 (0.53) 2.98 (0.62) 3.04 (0.86) 72 (12) Kit 2 3.30 (0.52) 2.93 (0.57) 3.07 (0.71) 69 (14) Kit 3 3.17 (0.65) 2.82 (0.61) 2.96 (0.78) 66 (15) Post-test 64 (11) 3.10 (0.60) Acknowlegements This research was supporte by the German Research Founation (DFG) within the research project on context-oriente learning in biology an chemistry (SA 1712/1-2 un SU 187/7-1) in the Research Training Group Teaching an Learning of Science (nwu-essen). References Anerwal I (1998) Freihanversuch Druck So funktioniert unser Herz. 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Naturwissenschaften im Unterricht Biologie. 27 (1) 45-49. Marion Haugwitz (corresponing author) is a postoctoral Researcher, National Eucational Panel Stuy (NEPS) at the University of Bamberg, Germany. Email: marion.haugwitz@uni-bamberg.e. Angela Sanmann is Professor of Biology Eucation at the University of Duisburg-Essen, Germany.
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