Published on October 2, 2007
Slide1: Attracting students towards physics A matter of topic? Laurence Viennot LSDP, University Denis Diderot (Paris7) Research on students’ motivation: Research on students’ motivation A large part of this research domain is mainly focused on topics likely to raise interest in young people ex: ROSE Schreiner & Sjøberg, 2005 A few studies also explore other aspects (type of activity, context) likely to attract students’ interest ex Häussler et al.,1998; Stark & Gray, 1999; Lavonen et al., 2005; Trumper, 2006 Searching for exciting topics: In recent school curricula or university syllabuses : a search for topics that are relevant (physics in context), exciting (« new », beautiful , makes you dream, incredible…) preferably: both Popularisation papers or events (ex: year 2005): - same concern But… Searching for exciting topics Attracting students towards physics: an irrecductible alternative?: Attracting students towards physics: an irrecductible alternative? Formalism: a stress to keep hidden? What about the value of the internal consistency, conciseness , and predictive power of physical theories? What about the pleasure of reasoning? The nature of science: distorted? What do we do with (reputedly) attractive topics?: What do we do with (reputedly) attractive topics? -How to make old topics (usefully) attractive? From the standpoint of: the value of the internal consistency, conciseness and predictive power of physical theories Appeal of « new » topics: Appeal of « new » topics Durban (ICPE 2004) « What physics should we teach ? » Quantum gravity for undergraduates? R. de Mello Koch A unit on (...) determinism and chaos for introductory physics students P. Laws Illustrating quantum entanglement in an elementary context G. Roston et al. Quantum mechanics for everyone: can it be done with technology? D. Zollman An example: « New » topics: with technology: « New » topics: with technology Quantum mechanics for everyone: can it be done with technology? D. Zollman Getting round a discouraging formalism http://web.phys.ksu.edu/vqm/ …for high school students and for non-science college students Slide8: … discrete states in quantum wells. The (…) program enables students to match wave fonctions visually at boundaries. They find that if they pick a random energy for a particle in a square well, the wave function does not fit* at both boundaries. *i.e.: they cannot obtain « smoothness » They get the functions matched up on one side, then try to meet the conditions on the other side. They can’t do it. Only for certain energies can they meet the boundary conditions on both sides. Slide9: To give a first idea of…, students in an active attitude, excited… A priori: undeniable positive outcomes, What did they learn? Only for certain energies can they meet the boundary conditions for both sides…: Only for certain energies can they meet the boundary conditions for both sides… What does it mean to « learn the material »? Concepts and links between concepts? Given this simulation, what is their view of the generalisability of what they see? What is the kind of reasoning that students are expected to use, on the basis of their « learning »? (in the absence of a computer) Our testing indicates that they are learning the material Some non-obvious questions A « new » topics: with (transparent) technology: A « new » topics: with (transparent) technology A unit on (...) determinism and chaos for introductory physics students P. Laws Slide12: Priscilla Laws Slide13: net = grav + damping + springs + driver . I= mR2 + 1/2( MR2 ) Iterative spreadsheet modeling Slide14: To give a first idea of…, students in an active attitude, … A priori: undeniable positive outcomes, What did they learn? Slide15: Finding a map for this jungle? Slide16: Several interrelated concepts ... to understand, (…) …, that determinism is there… « Students are asked to observe the natural oscillation frequencies of the apparatus when it is configured in different ways. This helps them understand why the system motion becomes chaotic when driven at certain frequencies. » … although « the system motion becomes chaotic when driven at certain frequencies. » Why? Instructors expected them to be surprised that the state of a chaotic system is unpredictable when the torques acting on it are known. Instead, students often commented that Laplacian determinism is not feasible because of quantum effects.: Instructors expected them to be surprised that the state of a chaotic system is unpredictable when the torques acting on it are known. Instead, students often commented that Laplacian determinism is not feasible because of quantum effects. …, we found that the Chaos Unit is both vexing and exciting to our students. What did they learn? Non-obvious questions…: Non-obvious questions… Beyond « showing » students that their predictions fail to describe what happens, how do we take into account students’ common ideas ? Non-obvious questions…: Non-obvious questions… Beyond working with a particular device, and « seeing » …, do students grasp some concepts, links between concepts, understanding of the generalisibility, idea of a domain of validity feeling of having an explanation (beyond a phenomenology) tools available to reason about a new situation ? …not to be overlooked, whatever the approach: simulation, analytical, analogical… A « new » topic with simple tools to reason: A « new » topic with simple tools to reason Imaging Ogborn and coll. 00, Advancing physics (AS-UK) Pixels, resolution, logarithmic scale, information in imaging, image processing « New » , « in context » ,. A set of interrelated concepts and enabling students to reason. Replace each pixel by the mean of its value and those of its neighbours …median… « New » topics: mission impossible?: « New » topics: mission impossible? Certainly not, but a need for thorough reflexion, careful selection of goals and strategies… Slide22: The question is not so much to get round the formalism as to - provide students with some tools for reasoning in order to help them go further than being «both vexed and excited ». A need to evaluate the innovative sequences From the standpoint of: the value of the internal consistency, conciseness and predictive power of physical theories Komorek & Duit IJSE 04 Ordinary topics and the value of internal consistency: Ordinary topics and the value of internal consistency Physics as an internally consistent and unifying description: an attractive idea?: Physics as an internally consistent and unifying description: an attractive idea? If yes, then it is worth considering the risks of inconsistency some possible ways of showing the limited but great power of physics An example with a very ordinary topic … Slide25: pO pO pO pO A hot air balloon …a total mass of… Whatever the temperature of the air in the balloon, its pressure will be the same as the surrounding air. (……….) …Show that to achieve the lift off…must be heated to about ….° C. A typical exercise: A hot air balloon Slide26: Archimedes upthrust : a matter of weights Mair-inside = rair-inside V Mair-outside-sameV = rair-outside V Fbasket+… + gMair-inside = gM air-outside-sameV Tin pin = pout = p 0 Tout F r = Mmol p0/RT Serious consequences: Serious consequences pO pO pO pO g Archimedes, where are you? But… « Local » ignores « global » and vice versa... Slide28: pin = pout pin > pout pin> pout P Global and local reconciled Dh Global Archimedes OK Aperture Viennot 04 Students’ reactions: Students’ reactions No spontaneous detection (1st year: 15 interviews* + degree: N=32*+16**) (same for 76 Teachers*) Guided analysis (1st year: 15 interviews*, degree: 21*+15**) -accessible , -takes time but worth it -raised pleasure Viennot 04*, 06* Mathé Viennot 07** A student: using critical sense: needs to be taught Slide31: The mean force (in time) exerted by this particule on the box equals the weight of the particule True or false ? The weight of a gas… only one molecule A particule moving vertically in a motionless box, elastic collisions on the walls An elastic collision …: An elastic collision … A molecule (m) hits a wall perpendicularly with a velocity v et leaves this wall with velocity -v. Change in linear momentum of the particule: Dp= -2mv v Slide33: Change in linear momentum of the particule at the top of the box Dptop= -2m (v + D v) u D v<0 Change in linear momentum of the particule at the bottom of the box Dpbottom= 2mv u Change …during a « cycle » due to the box (up and down, two collisions) Dpparticule,cycle = -2mDv u Slide34: Mean force exerted on the particule by the box during a cycle (2 Dt where Dt is the duration of free fall) fmean force box-on-particule = Dp/2Dt Free fall Dv = -g Dt u f mean force box-on-particule = mg u v = (v+ D v) u v (-u) Change …during a « cycle » (up and down) due to (two collisions with) the box Dpparticule, cycle= -2mDv u u Slide35: The mean force exerted by the particule on the box is equal to its weight v = (v+ D v) u v (-u) f mean force box-on-particule = mg u f mean force particule-on-box = -mg u Third law Therefore It had to be so: It had to be so The mean position (in time) of the centre of mass of the particule during a cycle is the same for all the cycles f mean force box-on-particule + ( -mg) u = 0 f mean force box-on-particule = mg u A Newtonian balance of forces : U Links between: Links between statics et dynamics individual et collective « it has to be so… » and «because» An inhomogeneous slice Slide38: A few reactions Destabilised trainee teachers (first professional year, N=19) : Destabilised trainee teachers (first professional year, N=19) The mean force exerted by the particle on the box is equal to its weight? The molecules, via collisions, exert the same force on the ground as if all the molecules of the column above were pile up, motionless, on the ground . Is it true that … A slice of atmosphere … , the force df exerted on it by the air around ... and its weight dP are such that dP + df =0 , with dP=-g(z)dzdS u The weight of a column of atmosphere equals the force exerted on the ground by this column Y N ? 5 10 4 5 9 5 8 3 8 11 5 3 Students’ reactions (3rd year univ., N= 13; trainee univ. teacher, N=9): Students’ reactions (3rd year univ., N= 13; trainee univ. teacher, N=9) Guided analysis (in group, 20mn) -accessible , -worth the time it takes -raised pleasure - never thought before z+Dz z Students’ reactions , more details(3rd year univ., N= 13): Students’ reactions , more details (3rd year univ., N= 13) Explains simply a fundamental question that is not very easy to explain simply to students intuitively. (4,4) - I like thinking about things that I never thought about before. (4,4) First question about a column of atmosphere: Yes 13/13 Then, question about a unique molecule: Yes 1/13 Then, the preceding analysis is presented: Students’ comments Slide42: Finally (without interval): Slide43: (Only one, « agitated », molecule in the box) -P1 It comes down to saying being at the botttom of the box and therefore… transmitting the weight, uhm, by the bottom of the box or moving all around the box and exerting actions, pressing forces,… it comes to the same thing. Why does it come down to the same thing… uhm…???? (After explanation) -P1 Oh yes, it’s because usually, when we study a gas, we neglect weight… we do not do it in a gravitational field … …We have shown in that box there why the pressure was greater than there, we have shown it with g. An experienced teacher, interview From the gas in a horizontal test tube to an atmosphere: From the gas in a horizontal test tube to an atmosphere From macro-global A continuity of mutually consistent viewpoints, in the frame of Newtonian mechanics From the hot air balloon to the single molecule and macro-local to nanoscopic Slide45: Ordinary topics, but less common questions… In general terms, students’ declare their appreciation …: In general terms, students’ declare their appreciation … Limited inquiry Slide47: Reasons for satisfaction: students’ ranking (1: very high) 29 3rd year univ-students Slide48: …a stress on coherence, and on links. Two lines of action -Many situations, a unique formalism -A unique situation, different approaches Many situations, a unique formalism …: Many situations, a unique formalism … The harmonic oscillator (60s) √N, Poisson, exp-t/t: radioactive decay etc See Advancing Physics IoP (UK, 2000- Ogborn, in particular: Imaging++) , Grade 12 in France (2000) Boltzmann factor, Change and Chance (Black,Ogborn, 70s),… Advancing Physics A2 (2001) And also d=vt (Viennot/Leroy: delayed signals GIREP sem.2004) Slide50: but also …different viewpoints for a given situation See also macro-meso: Besson Viennot 04 Final comments: Final comments Slide52: without a strong exigence of consistency, dislocated physics a near certainty Strong concern for consistency and links Intellectual satisfaction A linkage worth exploring further Slide53: If teachers agree to try …. …provided we are taught how to do it » « It’s worth it… « Good for us, not for them » Inciting teachers to try…what can we do?: Inciting teachers to try… what can we do? Teacher optimism: to be increased: Teacher optimism: to be increased Rational factors (2 =20,38, p=0,001). Emotional factors …creating the conditions for them to hear: Thank you, you have made me think « Good for us, not for them » The conditions for teachers to hear…: The conditions for teachers to hear… …… commonly thought of as limited to non-classical activities (projects, SPU,…) with « relevant » , « exciting », …topics ? …. raise intellectual satisfaction with ordinary topics Suggestion: consider it possible and necessary to Some references: Some references VIENNOT L. 2004, ICPE meeting, Delhi VIENNOT L. 2006.Teaching rituals and students' intellectual satisfaction, Phys. Educ. 41 pp. 400-408. http://stacks.iop.org/0031-9120/41/400. MATHE, S. and VIENNOT, L. 2007, The concern for coherence among future science mediators, ESERA meeting Malmö. VIENNOT L. & LEROY J.L. 2004. Doppler and Römer: what do they have in common? Phys. Educ., vol. 39, issue 3, pages 273 - 280. BESSON, U. & VIENNOT L. 2004. Using models at mesoscopic scale in teaching physics: two experimental interventions on solid friction and fluid statics, IJSE, 26 (9), pp1083-1110. [email protected] Slide59: Häussler, P., Hoffman, L., Langeheine, R., Rost, J. & Sievers, K. 1998. A typology of students’ interest in physics and the distribution of gender and age within each type. International Journal of Science Education, 20(2), 223-238. Lavonen, J.; Juuti, K.; Uitto, A.; Meisalo, V. & Byman, R. 2005. Attractiveness of Science Education in the Finnish Comprehensive School (pdf). In A. Manninen, K.Miettinen & K. Kiviniemi (Eds.), Research Findings on Young People’s Perceptions of Technology and Science Education. Mirror results and good practice. Helsinki: Technology Industries of Finland. Schreiner, C. & Sjøberg, S. 2005. Empowered for action? How do young people relate to environmental challenges? In S. Alsop (Ed.), Beyond Cartesian Dualism. Encountering affect in the teaching and learning of science. Dordrecht: Springer. Stark, R. & Gray, D. 1999. Gender preferences in learning science. International Journal of Science Education, 21(6), 633-643. Slide60: Key words Consistency Unifying power Functional thinking Durban 2003, ICPE « New » topics: with analogy: « New » topics: with analogy Komorek & Duit (04 and before)… entry: a phenomenology Known laws Limited predictibility « Often in an instable situation » « Sensitive, labile states of equilibrium » Why? « … due to a large number of variables » Why? Professeurs en formation, quatre questions de suite (PLC2, N=19) : Professeurs en formation, quatre questions de suite (PLC2, N=19) Réponses identiques O N ? Aux quatre questions 2 2 à trois questions seult à deux questions seult 0 1 0 1 1 0 0 2 0 5 1 1 1 7 1 A « new » topic with simple tools to reason: A « new » topic with simple tools to reason Imaging Ogborn and coll.. 00, Advancing physics (AS-UK) Pixels, resolution, logarithmic scale, information in imaging, image processing « New » , « in context » ,. A set of interrelated concepts Very large implications, domain of validity and enabling students to reason. Return to the atmosphere: Return to the atmosphere This reasoning is valid no matter what the value of v. It applies equally well to the vertical component of any non-vertical particular velocity. The collisions between particles keep the same quantity of motion. The fact that they can intervene during the period considered does not change the mean force exerted over time by the molecules on the sides or the bottom of the box.