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Virtual Lab Ripple Tank Model & Real Ripple Tank Interference Model Mr Ong Chee Wah (IJC), Mr Ng Soo Kok (IJC)Ms Lim Ai Phing (RVHS), Mr Lee Tat Leong (RVHS)Mr Wee Loo Kang (Senior Specialist) Education Technology Division, MOE

Redesigning Pedagogy International Conference Thinking : Time for a Rethink?4 Jun 2013, 10.30am to 12.00nnSymposium SYM001aNIE 7 01-TR706

A Big thank you to OSP

F. Esquembre, F-K Hwang, W. Christian, D. Brown ,M. Belloni, A. Cox, A. Duffy, T. Mzoughi ,, M. Gallis, T. Timberlake, J. M. Aguirregabiria, W. Junkin, H. Gould J. Tobochnik, Jose Sanchez, S. Tuleja and many more.Digital Libraries http://www.compadre.org/OSP/ +500http://www.phy.ntnu.edu.tw/ntnujava/index.php +2000+65 computer models are already customized, work with AST on LCMS

Introduction to Open Source Physics EJS2Proposed OrderStatic DisplayVideo DisplaySimulation Interactive Introduction to Open Source EJSActual Ripple Tank vs EJS Ripple TankTwo independent action research projects IJC and RVHS. Methodology and ResultsExpt groups which have access to EJS tend to perform better than their control group counterpart. However, results are inconclusive as there may be other external factorsEvaluation and Students Feedback Implication for self-directed learning and collaborative learning Proposed OrderRedesigning Pedagogy How to design appropriate worksheets. To be more reflective on how to use simulation .To increase learning for different ability groups. ConclusionResponses were generally in favour of EJS but some felt that they were more comfortable with a teacher-guided approach in the learning process.Both projects positively indicate the potential of using EJS in teaching and learning. EJS is but a tool. Designing the worksheets that is appropriate to their ability still poses a challenge. The projects have made us more reflective in our quest to redesign pedagogy to cater to different ability groups and different learner (multiple intelligence) group.

1. Introduction1Coetze & Imenda (2012)2Dede, Slazman, Loftin & Sprague (1999)3Chabay & Sherwood (2006)Many students have difficulty understanding waves and the principle of superposition. 1 They held various alternative conceptions due to the abstract nature of the topic. 1This could be due to the lack of real-life experiences and the appropriate contextualization of the phenomenon.2The time varying dynamic nature of waves makes the topic more difficult to conceptualise. 3

State the difficulty of study this topic

1. IntroductionThe ripple tank has traditionally been used to teach superposition of waves (or interference).The classic Ripple Tank Apparatus

Limitation of Ripple Talk Demo

1. IntroductionLimitationDifficulty in manipulating the variables.Difficulty in viewing and tracking the spatial changes as it happens.Bulky and cumbersomeThe classic Ripple Tank Apparatus

1. IntroductionWhich clip shows the two wave sources to be in phase?Which clip shows the two wave sources to be in antiphase?

Hint : There are two tell tale signs.

Case in point. What happens when the two sources are in phase and then antiphase?The top video has the sources in phase. Evidence : Principal Axis is Antinodal line. Also when video stops, both spots is bright.The bottom video has the sources in antiphase. Evidence : Principal Axis is Nodal Line. Also when video stops, one spot is bright while the other is dark.

1 IntroductionThe Virtual Laboratory Ripple Tank Interference Model was developed by Andrew Duffy (2010)and by Fu-Kwun Hwang and Wee Loo Kang (2012).The Virtual Laboratory Ripple Tank Interference Model (Easy Java Simulation)http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=2067.0It was developed to cater to the demands of the A-level syllabus.Comes complete with graphs and displacements bars. Attempts to stimulate real time interaction between two wavesAdvantage : It has visual and interactive application

http://weelookang.blogspot.sg/#!/p/physics-applets-virtual-lab.htmlhttps://dl.dropbox.com/u/44365627/lookangEJSworkspace/export/ejs_Ripple_Tank_Interferencewee07try.jar

Accessing the Ripple Tank Easy Java SimulationIf have time to show them the Simulation.10

Phase difference = 0Phase difference = 180o11

1. IntroductionThe Virtual Laboratory Ripple Tank Interference Model was developed by Andrew Duffy (2010) and modified by Wee Loo Kang (ETD) (2012).Easy Java Simulation (EJS)

Easy Java Simulation (EJS)

Easy Java Simulation (EJS)

Easy Java Simulation (EJS)

2 MethodTimelineExpt Group did the EJS in a computer laboratory.

Control Group observed a live demo on Ripple Tank

Time (2012)Expt GrpControl GrpT1 W6 (mid Feb)Completed Lecture on SuperpositionT1 W7 (late Feb)Pre Test(n=76)Pre Test(n=91)T1 W8 (early Mar)Easy Java SimulationLive Ripple Tank Demo.T1 W9 (mid Mar)Post Test(n=76)Post Test(n=91)T2 W2 Focused Group Discussion(n=12)At Innova Junior College

2 MethodThe Pre-Test consisted of some MCQs and short structured questions to assess their understanding of the topic on Superposition. Pre-Test (Max Marks : 24)

2 MethodExperimental Group had a teacher to guide them through the worksheets on the uses of the various buttons.

Experimental Group

2 MethodThe Google doc. has Activitiesand Tutorial Questions which require them to use the EJS to find the answers.

Experimental Group

2 MethodThe students are required to write their reasoning in the spaces provided while using the EJS. They can give their comments after each activities.Experimental Group

2 MethodThe EJS serves to encourage self-directed and collaborative learning.

Experimental Group

2 MethodThey can explore the 3D representation of the changes occurring during the wave superposition. Experimental Group

2 MethodBy manipulating the variables, they can view the outcomes immediately.

They can return to the website to explore further.Experimental Group

3 ResultsStand.Mean.Diff. Or Positive Effect Size.Trimmed to (Nexpt=53, Ncont=59) equivalent grouping of students with similar Pre Test Scores to see changes in Post Test Scores.

Actual Number of students andEquivalent numbersPre / 24 maximumPost / 24 maximumDifference= Post - PrePercent ChangeStandardized mean difference= (Expt Control)/SDExpt Grp765313.49 4.8913.09 3.7 16.06 5.0416.00 4.7 2.62 4.572.91 4.712.1%0.010.19Control Grp915913.84 4.7914.00 3.9 16.16 4.9416.00 5.2 2.58 5.151.95 4.88.1%-0.01-0.19Expt Group had a better score from Control Grp by 4.0%

Effect Size = +0.19

3 ResultsHake (1998)Assuming equivalent grouping of (Nexpt=53, Ncont=59) The 4% outperformance (12% gain compared to 8%) and Standardised Mean Difference = 0.19 may be modestBut it does suggest the potential of learning activities involving students in guided inquiry using computer with Ripple Tank Interference Model to promote and deepen students understanding.

Students survey (N = 42)

QuestionsStrongly disagree1234Strongly agree5Survey (4,5) insights1. I enjoyed learning about physics through this lesson5 (12%)2 (5%)6 (14%)17 (40%)12 (29%)>60%2. The lesson meet schools, teachers and pupils needs4 (10%)5 (12%)6 (14%)14 (33%)13 (31%)3. this lesson prepare you for life instead of just for examinations6 (14%)6 (14%)13 (31%)10 (24%)7 (17%)>40%SDL1 Ownership of Learning - self-directed learning?4 (10%)4 (10%)4 (10%)14 (33%)16 (38%)>60%SDL2 Management and Monitoring of Own Learning - self-directed learning?4 (10%)5 (12%)7 (17%)15 (36%)11 (26%)SDL3 Extension of Own Learning - self-directed learning?5 (12%)5 (12%)5 (12%)16 (38%)11 (26%)CoL1. Effective Group Processes - collaborative learning?3 (7%)5 (12%)10 (24%)13 (31%)11 (26%)>57%CoL2. Individual and Group Accountability of Learning - collaborative learning?5 (12%)3 (7%)10 (24%)14 (33%)10 (24%)

River Valley High Schools Approach Time (2012)Expt GrpControl GrpT3 W3 (9-13 Jul)Introductory Lecture on Superposition and Pre-TestT3 W4 (16-20 Jul)E-Learning Module with Ripple Tank Model (EJS) and Lectures on SuperpositionT3 W5 & W6(23 Jul-3 Aug)Tutorial with Ripple Tank Model (EJS)Normal TutorialT3 W7 (6-10 Aug)Post Test and Survey

ApproachOnline E-learning Module across the RV year 5 cohortPremised on the effect that the more times they used EJS, the better their exam scores.

RVHS

Approach

2. The Superposition Tutorial was conducted with simulation (EJS) used by teacher to go through some tutorial questions. http://tinyurl.com/6Ktutorial

ApproachSuperposition Tutorial

http://tinyurl.com/6Ktutorial

Evaluation (quantitative)Pre-Test 16 Past Year Multiple Choice Questions Post-Test 24 Past Year Multiple Choice Questions (Pre-Test with 7 added questions)Test scores converted to % for comparison.

Evaluation (quantitative)Question 24 in Post-Test:On how many occasions have you used or seen others use the java applet (Ripple Tank Simulation) for e-learning?A1 time (during e-learning)B2 times (during e-learning, tutorial, etc)C3 times Dmore than 3 times

results and learning (pre- & post- tests)Analysis of variance (ANOVA) on pre- & post-test (N = no. of times student used applet)NMeanStd. DeviationStd. Error95% Confidence Interval for MeanMinMaxLower BoundUpper Bound05630.6313.9191.86026.9034.3567011845.8317.3624.09237.2054.47227422047.6519.3644.33038.5956.7113833844.0012.8404.54033.2754.7335744748.4313.3525.04736.0860.783565Total10938.3917.2601.65335.1141.66683results and learning (pre- & post- tests)Analysis of variance (ANOVA) on pre- & post-test (N = no. of times student used applet)Statistically significant difference between pre- and post- tests for all cases of N = 1 to 4.Sum of SquaresdfMean SquareFSig.Between Groups7045.92741761.4827.290.000Within Groups25127.889104241.614Total32173.817108Evaluation (qualitative)Questionnaire to evaluate RVHS Ripple Tank Simulation lesson

results and learning (comments extracted from survey responses)The applet makes learning more visual thus making it easier to understand the topic of superposition. we can explore the applet by ourselves and find out relations between the various variables.strength is that we can go at our own pace for elearning, more active in learning as we are not fed with information but are actively exploring instead

3 Results

Focused Group Discussion among Expt Group (n=12)Pros1. It is visually appealing.2. It is interactive, being able to see the changes in real time when the parameters are changed. 3. It is more engaging and able to sustain interest and learning.4. The fact that they can carry out the simulation at their own pace for independent self-directed learning.

3 Results

Focused Group Discussion among Expt Group (n=12)Cons1. The many buttons can be confusing. They are rather crammed and they had difficulty maneuvering the cursor.2. The screen and font size are rather small.

ConclusionEJS does add a new and exciting dimension to the teaching and learning of Superposition.The results though encouraging is not conclusive as there may be other factors.EJS is but a tool. It is how we utilise it that brings to question of its relevance. Catering to groups of multiple ability still posed a challenge. Room for exploration.