The purpose of this study was to investigate the value of combining physical manipulatives with virtual manipulatives with respect to changes in students’ conceptual understanding of electric-circuits, and to compare the effect of virtual manipulatives and physical manipulatives on students’ understanding of concepts of electric circuits that were introduced in the parts of the study’s curriculum where physical manipulatives were substituted by virtual manipulatives. A pre-post comparison study design was used that involved 119 undergraduate students that attended an introductory course in physics. The participants were randomly assigned to two experimental and one control group. All groups used the same inquiry-based curriculum. Participants in the control group used physical manipulatives to conduct the study’s experiments, whereas, participants in the experimental groups used both physical and virtual manipulatives, but in a different combination. Conceptual tests were administered to assess students’ understanding before, during, and after the study. The data analysis involved both quantitative and qualitative procedures. Results indicated that the combinations of physical and virtual manipulatives enhanced students’ conceptual understanding more than the use of physical manipulatives alone. Additionally, the use of virtual manipulatives alone enhanced students’ conceptual understanding, in the parts of the study’s curriculum where physical manipulatives were substituted by virtual manipulatives, more than the use of physical manipulatives alone.

Aims

During the past decade there have been many optimistic claims about the potential of virtual reality to enhance science laboratory teaching and learning (Barab et al., 2000). In spite of these findings, some researchers have seriously questioned whether laboratory experimentation in science education, as we experienced it through Physical Manipulatives (PM), should be redefined and restructured to include Virtual Manipulatives (VM), (Zacharia, in press). This study was designed in an attempt to contribute towards this direction by investigating (a) whether the effect of experimenting with PM on undergraduate students’ conceptual understanding of electric circuits changed when PM were complemented with VM in different combinations within the study’s curriculum and (b) how the effect of experimenting with VM and PM on students’ conceptual understanding of electric circuits compared at different parts of the study’s curriculum.

Methodology/Research design

The participants of the study were 119 undergraduate students (21 males, 98 females), enrolled in an introductory course in electric circuits that was based upon the Physics by Inquiry curriculum (McDermott and The Physics Education Group, 1996, p.382), intended for pre-service elementary school teachers. The course took place at a university in Cyprus. The participants were randomly separated into three groups, namely, the Control Group (CG, 40 students), the Experimental Group 1 (EG1, 40 students) and the Experimental Group 2 (EG2, 39 students). None of the participants had taken college physics prior to the study.  

A pre-post comparison study design was used for the purposes of this study that involved two experimental groups (EG1 and EG2) and a control group (CG) according to diagram 1.

[Insert Diagram 1 about here]

Conceptual tests were administered to assess students’ understanding of the electric circuits both before and after the study (Electric Circuit or EC Test), as well as, both before and after introducing each part (A, B and C) of the study’s curriculum (see Diagram 1). The tests were developed and used in previous research studies by the Physics Education Group of the University of Washington (e.g., McDermott and Shaffer, 1992).

The data analysis concerning the first research question involved (a) paired-samples t-test for the comparison of the EC pre-test scores to the EC post-test Scores of each group and (b) ANCOVAs for the comparison of the EC post-test scores of the three groups. The aim of the first procedure was to investigate whether the use of the two combinations of PM and VM (EG1: PM+PM+VM and EG2: PM+VM+PM), and the use of PM alone (CG: PM+PM+PM), within the context of the Physics by Inquiry curriculum, improved students’ conceptual understanding. The aim of the second procedure was to investigate (i) whether the effect of PM on undergraduate students’ conceptual understanding of electric circuits changed when PM was complemented with VM and (ii) which combination (of the EG1, EG2) was better.

In order to address the second research question, a comparison was made across the three groups for Parts B and C of the curriculum. The relevant data analysis involved analyzing qualitatively and quantitatively data collected through the pre- and post-tests 2 and 3. The quantitative part involved the ANCOVA procedure in order to investigate whether the substitution of VM for PM had a different effect on students’ conceptual understanding of Parts B and C of the study’s curriculum. The qualitative data analysis focused on identifying and classifying students’ scientific (SAC) and non scientific conceptions (NSAC) concerning measurements of current and resistance (Part B) and measurement of voltage (Part C). The analysis followed the procedures of phenomenography (Marton 1981; Marton & Booth 1997). In addition, the prevalence for each one of the resulting categories for each test was calculated. The purpose of the latter was to compare if the prevalence of each category of students’ conceptions differed prior to and after Parts B and C because of the substitution of VM for PM.

To ensure objective assessment, the tests were coded and scored anonymously. Internal reliability data were also collected. Two independent coders reviewed 25% of the data. All the reliability measures were above 0.88.

Results and Discussion

The quantitative analysis showed that both of the combinations of PM and VM and PM alone improved students’ conceptual understanding after the study. However, the ANCOVA and post-hoc comparisons designated that the students of the EG1 and EG2 had significantly greater EC post-test scores than the students of the CG after the study. No statistical difference was found between the EC post-test scores of EG1 and EG2. Moreover, ANCOVA and post-hoc comparisons revealed that the substitution of VM for PM had a significant effect on students’ conceptual understanding of Parts B and C. It was found that the EG1 had significantly higher scores on post-test 3 than the CG, and EG2 had significantly higher scores on post-test 2 than the EG1 and CG. No statistical difference was found between the post-test 3 scores of EG1 and EG2.

The phenomenographic analysis revealed that the ideas of these three groups appeared to be organized in roughly the same categories of conceptions, either SAC or NSAC across all parts (A,B and C). In addition, it was found that the prevalence of each category (SAC or NSAC) of each group was about the same in both pre-test 2 and pre-test 3, whereas, in post-tests 2 and 3, the EG1 had a larger shift from NSAC to SAC concerning the measurement of voltage (Part C) than the EG2 and CG, and EG2 had a larger shift from NSAC to SAC, concerning the measurement of current and resistance (Part B), than the EG1 and CG.

Conclusion

Studies in this domain are particularly important because they could, ultimately, answer potential questions on how science experimentation could be developed to become more effective in terms of promoting conceptual understanding.

References

Barab, S.A. et al. (2000). Journal of Science Education and Technology,9,7-25.

McDermott, L.C. et al. (1996). Physics by Inquiry. NY:Wiley