Substituting Traditional Hands On Laboratories with Computer Simulations What s gained and what s lost by Chris Keller Physics 4810 7810 Prof Noah Finkelstein Fall 2004 December 13 2004 Introduction Most introductory physics courses contain some sort of laboratory section and this is often the only segment of a course that allows students to be directly engaged with the content and observe physics in action Instructors have numerous goals and expectations for their students to achieve by completing these labs which include but are not limited to confirmation developing mechanical skills error analysis empiricism and concept building Occasionally laboratory curricula have attempted to provide students with an environment that to some extent resembles a research scientist If one were to instead replace this environment with a computer simulation that replicates physics concepts what would happen As one may expect there may not be a global answer to this question it may depend on the subject matter at hand the environment in which a simulation is introduced the characteristics of the user and the goals that an instructor has in mind To narrow down the focus this study will look at how one particular computer simulation known as the Circuit Construction Kit CCK affected Physics 1120 students conceptual understanding of DC circuits compared to their classmates who used real equipment There is reason to believe that CCK is better at helping students develop intuitive knowledge about current flow since the flow of electrons is explicitly shown in the simulation Thus far the results from this study show that students who used CCK performed slightly better than students who used real equipment when answering multiple choice questions on a course examination Background Computers have been used in classrooms for quite some time now Their function has been to supplement large lectures and acquire data and display those data in real time 1 2 3 4 5 6 We do find a few studies that look at replacing hands on labs with computer simulations 7 8 9 10 1 The focus of this study is similar to that Finkelstein et al where CCK was introduced into a different university environment and was shown to be more successful at developing conceptual understanding than a traditional laboratory The simulation used in this study was develop and tested by the Physics Education Technology PhET group at the University of Colorado at Boulder They have developed a variety of physics simulations that include most of the topics covered in a typical introductory physics sequence The simulations are also downloadable for free online 11 These simulations are designed to be interactive engaging and explicitly show various phenomenon 12 The simulation used in this study the Circuit Construction Kit allows students to build simple DC circuits with batteries wires resistors light bulbs and switches The simulation utilizes Kirkoff s law to accurately model current and voltage for a given circuit A workplace is provided where students can place various components connect them together and measure various properties with a virtual amp meter and volt meter In addition a key distinction between real circuits and their virtual counterparts is that CCK explicitly shows students the manner in which electrons flow through a circuit Students can see the way in which current splits and recombines at various points along the circuit This feature of course is not made available for students who use real batteries bulbs and wires This study was conducted in the Fall 2004 semester in Physics 1120 the second semester of a calculus based introductory physics sequence intended for engineering chemistry and physics majors In addition to lecture students meet weekly for a one hour recitation section where they work on tutorials from Tutorials in Introductory Physics 13 Among other topics the students completed two different DC circuit tutorials one on current and resistance and another on voltage p 97 106 Half of the recitations used real equipment to complete the tutorials and the 2 other half used CCK in place of real equipment The tutorials that the CCK students used were only slightly modified from the original version to make certain instructions clearer the questions and tasks were left unchanged Data Recall that the focus of this study is to see how CCK affected students conceptual understanding of DC circuits Thus verification is necessary that the experimental group CCK and the control group Real both have the same understanding of DC circuits prior to any intervention Before the students received any instruction the Brief Electricity and Magnetism Assessment BEMA exam was given to the entire course The BEMA exam is a 31 question multiple choice assessment survey covering most topics found in a typical second semester introductory physics course 14 Three additional questions on DC circuits were added to the exam All 6 questions on the BEMA exam relating to DC circuits were analyzed There are no statistically significant differences between the two groups on any of the questions see figure 1 DC Circuit Qs Pre BEMA 0 35 CCK Fraction Correct 0 3 Real 0 25 0 2 0 15 0 1 0 05 0 Q10 Q11 p 0 08 p 0 6 Q17 p 0 5 Q32 p 0 6 Q33 Q34 AVG p 0 5 p 0 09 p 0 5 Figure 1 Fraction correct of six questions on the BEMA exam relating to DC circuits All p values were obtained with the Fischer Test No question yields a statistically significant difference 3 During the two tutorials where CCK was used observations were taken to determine how students were using CCK and to look for common problems students were having when using the simulation Most students found the simulation fairly easy to use some problems were encountered at first but these were usually solved by one of the group members after some trial and error Occasionally a computer would crash or freeze up but these only caused minor delays and were not a major inconvenience for the students It was also noted that some groups of students were observed playing with the simulation trying to catch batteries on fire and building odd circuits Sometimes this occurred after the students had finished the tutorial but occasionally students would play with the simulation prior to the start of tutorial An exam was given four weeks after the second circuits tutorial the exam consisted of 15 multiple choice questions and two long answer questions that required students to give an answer and explain their solution Six