The Effects of Using Touch-Screen Devices on Students' Molecular

Aug 13, 2014 - The impact of touch-screen technology on spatial cognitive skills as related to molecular geometries was assessed through 102 one-on-on...
0 downloads 3 Views 362KB Size
Download PDF
Article pubs.acs.org/jchemeduc

The Effects of Using Touch-Screen Devices on Students’ Molecular Visualization and Representational Competence Skills Brett M McCollum,* Lisa Regier, Jaque Leong, Sarah Simpson, and Shayne Sterner Department of Chemistry, Mount Royal University, Calgary, Alberta T3E 6K6, Canada S Supporting Information *

ABSTRACT: The impact of touch-screen technology on spatial cognitive skills as related to molecular geometries was assessed through 102 one-on-one interviews with undergraduate students. Participants were provided with either printed 2D balland-stick images of molecules or manipulable projections of 3D molecular structures on an iPad. Following a brief introduction to common molecular shapes, participants were assessed on their representational competence. In particular, learners were tested on their ability to match and construct molecular representations. Using the device for less than 15 min, iPad users exhibited increased ability to correctly identify related chemical representations relative to learners taught with a paper-based method. Even in the last stage of the experiment, without access to the iPad, a significant difference between the two populations was sustained, with iPad-based learners demonstrating significantly higher representational competence than learners using the paper-based method. These findings suggest that touch-screen devices such as the iPad serve as effective learning technology for development of visuospatial and representational competence skills. KEYWORDS: Chemical Education Research, First-Year Undergraduate/General, VSEPR Theory, Computer-Based Learning, Hands-On Learning/Manipulatives FEATURE: Chemical Education Research plastic balls and connectors that permit particular fixed spatial arrangements that correspond with the geometries predicted by valence shell electron pair repulsion (VSEPR) theory.19−22 There are arguments for expanding the chemistry educator’s toolkit beyond physical models.23,24 Multiple learning modes for molecular modeling have been shown to improve student performance.25 It is now common practice to use both 2D images, such as those found in textbooks, and 3D physical models when teaching VSEPR Theory. However, use of molecular representations require learners to develop some level of representational competence, a spectrum of skills for interpreting, transforming, coordinating, and constructing external representations used when learning or problem solving within a specific domain.26−29 For instance, mathematics instruction of children involving multiple external representations draws heavily upon representational translation and coordination skills, the ability to translate between different representations and coordinate complementary information not necessarily found in both representations.30 In the field of chemistry, experts and novices can be identified based on their ability to translate and coordinate multiple representations of chemical phenomena.26 Harle and Towns provide an excellent review of research on spatial ability and how it can inform teaching and learning in chemistry.31 Chemical instruction must involve both content delivery as well as representational competence training.

I

nterpreting two-dimensional representations of objects in terms of their three-dimensional properties is a necessary skill in chemistry,1−4 as well as other fields such as biology, geology, geography, agriculture, and fashion.5−11 In addition to mathematical reasoning and verbal abilities, spatial skills are one of the major ability domains in the structure and organization of human abilities.12,13 Molecular representations play a fundamental role in chemistry in that they permit a scientist to infer behavior including state and reactivity.14,15 When reviewing the use of various representation systems to convey chemical information, Habraken says (ref 15, pp 90−91): Chemists cannot talk to each other without the use of drawings and, increasingly so, by using computer-generated pictures and molecular models. Because, in chemistry, the picture has become more than this; it has become a way of thinking and the dominant way of thinking. ... The evolution from the first primitive drawings of 125 years ago to today’s computer-generated drawings is a clear demonstration of the simultaneous evolution of a science and its scientific language. To the frustration of many chemistry neophytes, molecules are too small for all but the most sophisticated instruments to image.16 For this reason, chemists rely on modeling kits to train students on the three-dimensional structure of molecules.17 While it was once said that “painted balls connected by rods are less like real atoms than department-store mannequins are like real women”,18 these modeling kits continue to be an invaluable resource in chemistry. Modern modeling kits typically contain © XXXX American Chemical Society and Division of Chemical Education, Inc.

A

dx.doi.org/10.1021/ed400674v | J. Chem. Educ. XXXX, XXX, XXX−XXX

Journal of Chemical Education

Article

Instead, to reduce the length of the majority of interviews, a sample of 5 participants from each group was randomly selected and underwent the preassessment test prior to the remainder of the interview. Many statistical tests, such as the Mann−Whitney U-test, can be applied to samples of this size.35 The means scores for the paper and iPad groups were 12.2 and 11.8, respectively. Applying the two-tailed Mann−Whitney Utest to the results demonstrates that the two populations can be considered equivalent at a significant level of α = 0.05 (n1 = n2 = 5, U = 10 > 2 = Ucritical). Throughout the remainder of the interview, all participants completed the same exercises, the only difference being the medium used to present the molecular images.

With current students living and growing up in a technological age, many students have access to complex computer systems and games. Interactive computer software has been used to improve student success with molecular visualization.32,33 Furthermore, combined use of both physical models and computer images leads to improvements in students’ higher-order thinking skills.2 The iPad is a tablet computing device from Apple, Inc. that permits multiple simultaneous touches and gestures. The advent of touch-screen technologies, such as the iPad, provides a means to bring interactive computer images into the classroom, and this can easily be combined with molecular models in engaging learning activities. Herein we determine if the iPad can be classified as teachnology, technology that when used appropriately is an effective tool for teaching and learning. In this study, we focus on evaluating students’ matching (e.g., representational transformation) and construction (e.g., representational construction) skills when using either 2D printed images of molecules or manipulable 2D projections of 3D molecular images on an iPad. As would be expected in a classroom environment where students are interacting with multiple external representations from a variety of sources, the transformation exercises generally also required mental rotation of the representations. No attempt was made to isolate these two related tasks.

■

Data Collection

Interviews involved the five phases shown in Figure 1. Parts A and B of the interview were instructional, while Parts C−E were

METHODOLOGY

Participant Qualifications

Participation in the study was restricted to undergraduate students who had not previously taken General Chemistry I, or its equivalent at another institution. At our institution, the population in introductory chemistry is primarily science majors, but also includes students from diverse programs such as psychology, business, and aviation. To properly capture the mixture of abilities and backgrounds observed in introductory chemistry, participation was open to students in all faculties. However, a vast majority of volunteers were students in the first year of the BSc program and its feeder upgrading courses. Although all BSc students will have completed high school chemistry, their knowledge of molecular geometries is mostly limited to the shape of the water molecule. In total, 102 interviews were conducted with individual participants by one of four undergraduate research assistants. Research assistants strictly followed an interview script to maintain consistency. Participants were randomly assigned to one of two groups: paper-based or iPad-based learning. The distribution of participants according to gender (47 males, 55 females) is shown in Table 1. To determine if a difference existed between the two populations in terms of their preexisting visual-spatial ability a preassessment test using 16 Shepard and Metzler type mental rotation test items was employed.34 However, on the basis of funding limitations and the large number of participants (102 participants), it was not possible to provide this preassessment to all participants.

Figure 1. Interview process.

evaluative. Each stage had a time limit of 5 min. The maximum time a participant used the iPad was 15 min (Parts A, C, and D). Interviews were video recorded with the consent of the participant. Participants had not yet encountered VSEPR Theory in their coursework at the time of their interview, and thus, the purpose of Parts A and B were to introduce the participant to the molecular representations that were used throughout the remainder of the study. To simulate the time restrictions of a classroom learning experience, participants were limited to only 20 s per representation. Parts C and D were designed to assess the impact of the medium (paper or iPad) on participants’ matching skills. The final stage of the interview, Part E, was used to determine if the medium influenced participants’ construction skills. Learner inference skills were not examined in this study, but are the subject of future work.

Table 1. Distribution of Participants According to Gender and Provided Medium Learning Medium

Male Participants, % (N = 47)

Female Participants, % (N = 55)

Paper iPad

48 44

52 56 B

dx.doi.org/10.1021/ed400674v | J. Chem. Educ. XXXX, XXX, XXX−XXX

Journal of Chemical Education

Article

Figure 2. “Ball-and-stick” molecular representations used in Parts A−C of the study along with photographs of the corresponding physical models. The VSEPR names for the structures shown are (a) Linear, (b) Trigonal Planar, (c) Bent or Angular, (d) Tetrahedral, (e) Trigonal Pyramidal, (f) Trigonal Bipyramidal, (g) See-saw, (h) T-shaped, (i) Octahedral, (j) Square Pyramidal, (k) Square Planar.

The print images used in Part A were “ball-and-stick” representations of molecular geometries. Printed image are shown in Figure 2 alongside photographs of the corresponding physical models used in Part B. Participants were permitted to handle the print/iPad images and the physical models. To ensure that participants were establishing matches in Part C based on shape and not color, all molecular images were designed to have white atoms bonded to a central gray atom. Due to the available components in the modeling kits, the physical models used black balls for the central atom in all 2-, 3-, 4-, and 5-coordinate geometries, while the 6-coordinate shapes used a central gray atom. The same representations were presented to iPad participants using an iPad and the “Molecules” mobile app.36 This app renders ball-and-stick molecular representations that can be manipulated in a 3D virtual space through the iPad’s touch-screen interface. Molecular structural data for the VSEPR shapes used in this study are included in the Supporting Information. The primary difference between participant experiences was that iPad users could use the functionality of the iPad to manipulate the orientation of the image. In Part C, participants were presented with the same molecular images as in Part A and asked to identify the corresponding physical model from Part B. The order of the images was different from Parts A and B, but consistent throughout all interviews. For each proposed match, participants were told if their selection was correct or not before moving on to the next image. The purpose of informing the participant on the accuracy of each proposed match was to provide a small amount of feedback similar to a classroom experience. Before beginning Part D of the experiment, the iPad/paperbased images used in Parts A−C were taken away from the participant, but the physical models were left within reach of participants for reference. Participants were instructed on how to interpret structural formulas in terms of the 3D nature of wedged and hatched bonds (see Figure 3). Structural formulas

are not part of the provincial secondary school curriculum, and it is not expected that participants will have had prior experience with this type of representation. They were then given a sheet with a set of four numbered structural formulas. To avoid participants seeking nonverbal clues from the interviewer, they were provided envelopes labeled 1, 2, 3, and 4, corresponding to the four structural formula options. A single “ball-and-stick” molecular image (paper- or iPad-based) was then given to the participant, and they were instructed to open the envelope for the structural formula that matched the image and check if they were correct. When a match was proposed, a new set of materials was given to the participant for them to repeat the process with another molecule. If a second match was proposed before the time limit of 5 min was reached, then a third set of materials was presented. Each set of molecular images and structural formulas options used in the experiment is shown in Figure 3. Note that some of the colors for atoms do not match the standard colors used by chemists. This is a consequence of the limited options in the Molecules app. Before Part E, the iPad/paper-based images used in Part D were taken away from the participant, but the physical models were left within reach of participants for reference. For Part E, a single structural formula, shown in Figure 4, and a modeling kit were provided to participants. Participants were instructed to construct a physical model of the molecule with the correct 3D spatial arrangement of atoms. The scoring system implemented for each stage of the experiment was related to the design of the corresponding exercise. In Part C, students earned a score out of 11 points based on the number of correct matches. For each of the exercises in Part D, it was recorded whether participants identified the correct structural formula. The scoring system for Part E measured how closely their model matched key features of the correct structure. These features are listed in Table 2. C

dx.doi.org/10.1021/ed400674v | J. Chem. Educ. XXXX, XXX, XXX−XXX

Journal of Chemical Education

Article

Figure 4. (a) The structural formulas used in Part E of the study; (b− e) examples of participant responses. The correct answer is image b.

Table 2. Scoring System for Part E Item 1 2 3 4 5 6 7 8 9 10

Figure 3. “Ball-and-stick” molecular images and structural formulas options used in Part D of the study. (a) Option 2 is correct. (b) Option 4 is correct. (c) Option 3 is correct. The options for molecule D-1 are cis-/trans-isomers, while the options for molecules D-2 and D3 are stereoisomers. These topics are taught in organic and inorganic chemistry. This assessed how well learners could synthetically discover these types of spatial relationships without formal instruction.

Correct Characteristica

Key Feature Geometry at the carbon atom Geometry at the phosphorus atom

Tetrahedral Trigonal bipyramidal Geometry at the nitrogen atom Trigonal pyramidal Number of hydrogen atoms attached to the carbon 3 Number of hydrogen atoms attached to the 2 phosphorus Number of chlorine atoms attached to the 1 phosphorus Number of hydrogen atoms attached to the 2 nitrogen C−P−N bond angle 180° All atom colors match those listed below the structural formula Nothing extraneous on the model

a

One point was earned for each of the listed features that matched the correct model.

Table 3. Participant Performance on Part C Scorea

Paper-Based Participants (N = 48)

iPad-Based Participants (N = 54)

11 10 9 8 7 6 5 4 3 2 1 0

15 13 8 3 6 2 0 1 0 0 0 0

45 8 1 0 0 0 0 0 0 0 0 0

■

RESULTS Participant performance during Part C is reported in Table 3. A box-plot of the data is provided in Figure 5. The discrete-valued data sets follow exponential distributions and the appropriate statistical tool is Welch’s U-test.37,38 The significance level selected for this study was α = 0.05. In the case of Part D, the data is binary, and therefore, Fisher’s Exact Test is appropriate.39,40 Results are listed in Tables 4 and 5. Similar to Part C, data from Part E of the experiment are integer valued scores and thus were analyzed using Welch’s Utest. The results are given in Table 6 with a corresponding boxplot shown in Figure 6.

The Part C task involves matching physical models to provided “balland-stick” molecular images. a

D

dx.doi.org/10.1021/ed400674v | J. Chem. Educ. XXXX, XXX, XXX−XXX

Journal of Chemical Education

Article

Figure 6. Box-plot of participant performance in Part E as a function of technology (n[paper] = 48 and n[iPad] = 54). Those who had used the iPad in the earlier stages of the experiment generally were better at constructing a physical model. *P = 0.018 < 0.05.

Figure 5. Box-plot of participant performance in Part C as a function of technology (n[paper] = 48 and n[iPad] = 54). Many participants who used the iPad earned a perfect score of 11. *P = 4.6 × 10−7 ≪ 0.001.

■

Table 4. Participant Performance on the Three Exercises in Part D

Matching Molecular Representations

The results for Part C clearly demonstrate that students with access to the iPad outperformed their paper-based peers on the first assessment exercise. Although higher spatial ability on mental rotation tasks has been identified in males,41 the two populations had approximately the same gender distributions with a slighting higher female percentage in the iPad group. Thus, it is not expected that gender is responsible for the observed performance difference. The variance of performance was substantially lower for iPad users. This may suggest that the touch-screen is narrowing the performance gap between students. Alternatively, because most iPad users scored a perfect 11 on this stage of the experiment, this test was no longer able to differentiate between strong and weak learners among the iPad group. It is likely that the results are impacted by both factors. The difference in performance by the two populations (paper and iPad users) on both molecules D-1 and D-2 is significant. The difficulty of the tasks in this stage increased from locating a plane of symmetry to identifying centers of chirality. Approximately 20% of participants ran out of time before reaching D-3. Additionally, most participants who started the third structure did not have enough time and commented that they were guessing. Consequently, there is no significant difference between the two groups in the D-3 exercise, and the results for both groups correspond with random guessing within statistical errors. It was observed that iPad users took longer than paper-based learners on exercises C and D. While many participants using the iPad would randomly change the molecular orientation, perhaps to internalize the structure, a few discovered that they could adjust the image so that the bonds would match those of the structural formula and thus begin canceling out options where one or more groups could not be positioned correctly regardless of orientation. These purposeful participants performed better. The benefits of tactile interaction in chemistry has also been reported by Stieff.42 He observed that external actions on physical models improved student representational translation skills in organic chemistry when supported by expert instruction.

Participants’ Results, Nb Exercisea

Medium

Correct

Not Correct

D-1

Paper iPad Paper iPad Paper iPad

26 42 6 23 8 6

22 12 42 31 31 37

D-2 D-3 a

The Part D task involves identifying a structural formula that matches a provided “ball-and-stick” molecular image. bThe number of participants for Part D-3 is lower than the the number of participants for previous parts because many participants ran out of time before getting to this stage.

Table 5. Performance Statistics for Part D Exercise

Npaper, NiPad

Two-Tailed p-Value,a

D-1 D-2 D-3

48, 54 48, 54 38,b 43b

0.02 0.0009 0.56

a

A significant difference (α = 0.05) emerges between participants’ performance on exercises D-1 and D-2, but not D-3. This is likely the consequence of participants running out of time to complete the third exercise. bThe number of participants for Part D-3 is lower than the previous parts because many participants ran out of time before getting to this stage.

Table 6. Participant Performance on Part E Scorea

Paper-Based Participants (N = 48)

iPad-Based Participants (N = 54)

10 9 8 7 6 5 4 3 2 1 0

11 15 5 6 4 4 2 0 0 1 0

22 18 3 5 3 3 0 0 0 0 0

DISCUSSION

Constructing Molecular Representations

Examples of participant responses to Part E are shown in Figure 4. One of the most common mistakes in the paper-based group was a lack of recognition of the different types of positions (axial versus equatorial) surrounding the phosphorus atom and

a

The Part E task involves constructing a physical model from a provided structural formula. E

dx.doi.org/10.1021/ed400674v | J. Chem. Educ. XXXX, XXX, XXX−XXX

Journal of Chemical Education

Article

courses. Presumably, learners would adopt the mental processes practiced by experts that permit avoidance of complex timeconsuming visuospatial manipulations. This agrees with the observation that some groups of students demonstrate preference for algorithmic techniques over visuospatial manipulations when conducting chemical problem-solving.3 Another benefit of student use of tablets when studying molecular geometries is the time savings relative to having students construct physical models in lecture. Digital representations can be prepared by the instructor before lecture affording the time to explore a greater range of molecular structures in class, and delivery to each student’s tablet (via the course management site for instance) permits learner-centric interactions with the representation as compared to an instructor demonstration. Review of the video recordings revealed that iPad users performed an average of 30 hand gestures indicating mental rotation as compared to an average of only 1 rotation gesture for the paper-based learners. The disparity between groups is particularly significant in light of Goldin-Meadow’s findings that hand gestures can indicate and promote learning.48,49 Gesture had been shown to lighten cognitive loads and enhance learning mental rotation tasks.50−52 The improved construction ability of iPad users, even without access to the iPad, suggests that use of the tablet has enabled some foundational understanding or heightened spatial understanding of the molecular structure and connectivity not acquired by the average paper-based learner. This can be interpreted in the context of each representation’s design and functionality. Paperbased images are designed to be viewed; touching the page does not cause the image to change. On the other hand, the iPad is a multitouch device that responds to user interaction. Participants would frequently alternate between touching the iPad screen and gesturing. Our interpretation of this observation is that the incorporation of a touch-screen device into the educational experience promotes gesture, which in turn supports visualization and learning.

thus the linear relationship of the C−P−N moiety. Aligning with the other assessments, the mean scores for the two populations in Part E were found to be statistically different. Participants who used the iPad in earlier stages of the experiment did better at this construction exercise, even though they did not have access to the iPad during this assessment. On the basis of these results, the iPad, as a manipulable touch-screen technology, played an important role in bridging students’ visuospatial understanding between structural formulas and 3D physical models. The difference in performance cannot be explained by offloading of cognitive processes as the iPad was not used during the construction phase. While each of the stages of this study could have been conducted using a computer screen and mouse, it is unclear if the indirect manipulation would have yielded the same results as the tactile experience of the touch-screen tablet. Learner Approaches to Problem Solving

The experience of paper-based learners was very different from that of the iPad participants. Generally, the paper group did not pick up the image but rather left it resting on the table. Very few participants rotated an image or angled it relative to their eyes. In agreement with Smith’s observations on embodied cognition that cognitive development occurs when a learner interacts with their environment through sensory-motor activity,43 paper-based users found the exercises increasingly challenging and did not appear to develop coping techniques. As a result, the difference between the average performance of the two groups increased from exercise D-1 to D-2. This result is also consistent with previous research that the requisite representational competence and visuospatial skills for success in university chemistry must be developed through practice.2 The choice of initial orientation for the D-2 molecule may also have proven particularly challenging for the paper-based learners. It is important to consider that an alternative to participant familiarity with the touch-screen interface of the iPad is that learners might be off-loading cognitive processes onto the device. However, that should not be as much a concern as one might think. This off-loading process could be compared to the way scientists off-load menial computation to calculators, freeing them up to engage in more complex problem solving. Hambrick found that for geology novices, spatial ability was a good predictor of skill, mostly because the tasks expected of them required spatial ability and they had few coping techniques.44 In contrast, spatial ability was no longer a good predictor of skill in experts. Hambrick refers to this phenomenon as the “circumvention-of-limits”.45 Similarly, Stieff found that when working with representations of 3-dimensional molecules experts employed very different mental processes than novices, such as first identifying if planes of symmetry are present and only if none exist do they then attempt mental rotation.46 In this way, experts employ additional coping techniques and are less hindered by weak spatial ability than novices. Uttal argues that spatial abilities matter in STEM education simply because they are a barrier that novices must surmount before participating in more advanced topics.47 He proposes investments in spatial training on the basis that it could yield significant dividends in student success. This research suggests that widespread implementation of tablet technology in STEM education could help students surmount or even bypass the visualization barrier in introductory courses, increasing enrollment in upper-division and graduate chemistry

Implications for Teaching and Learning

In addition to demonstrating the impact of touch-screen technology on chemical education, this paper makes a strong case for the reformation of traditional educational materials, namely, the printed textbook. Simply digitizing existing content, as is the case for most current eBooks, is not sufficient. Static “ball-and-stick” molecular images should be replaced with manipulable molecular renderings. Without the real estate restrictions and printing costs per page, it should be possible for authors to provide complimentary representations to support development of representational transforming and coordinating skills. It should be kept in mind that our data supports the replacement of static paper-based images with manipulable digital ones. The data does not suggest any change in the use of molecular modeling kits. It is our opinion that manipulable molecular images in a three-dimensional virtual environment on touch-screen tablets serve to bridge student representational competence between two-dimensional structural formulas and three-dimensional physical models. All three modes of representation remain important in chemical instruction. Finally, success in university-level chemistry depends on a student’s ability to visualize a molecule, describe the spatial relationship of the atoms in various orientations, and predict how portions of that molecule will interact with its F

dx.doi.org/10.1021/ed400674v | J. Chem. Educ. XXXX, XXX, XXX−XXX

Journal of Chemical Education

Article

(4) Stieff, M.; Hegarty, M.; Deslongchamps, G. Identifying Representational Competence with Multi-Representational Displays. Cogn. Instr. 2011, 29, 123−145. (5) Lazarowitz, R.; Naim, R. Learning the Cell Structures with ThreeDimensional Models: Students’ Achievement by Methods, Type of School, and Questions’ Cognitive Level. J. Sci. Educ. Technol. 2013, 22, 500−508. (6) Lennon, P. A. Improving Students’ Flexibility of Closure while Presenting Biology Content. Am. Biol. Teach. 2000, 62, 177−180. (7) Kastens, K. A.; Agrawal, S.; Liben, L. S. How Students and Field Geologists Reason in Integrating Spatial Observations from Outcrops to Visualize a 3-D Geological Structure. Int. J. Sci. Educ. 2009, 31, 365−393. (8) Lloyd, R.; Hodgson, M. E.; Stokes, A. Visual Categorization with Aerial Photographs. Ann. Assoc. Am. Geogr. 2002, 92, 241−266. (9) Nielsen, C. P.; Oberle, A.; Sugumaran, R. Implementing a High School Level Geospatial Technologies and Spatial Thinking Course. J. Geogr. 2011, 110, 60−69. (10) Mitzman, S.; Snyder, L. U.; Schulze, D. G.; Owens, P. R.; Bracke, M. S. The Pilot Study of Integrating Spatial Educational Experiences (Isee) in an Undergraduate Crop Production Course. J. Nat. Resour. Life Sci. Educ. 2011, 40, 91−101. (11) Park, J.; Kim, D.-E.; Sohn, M. 3D Simulation Technology Aas an Effective Instructional Tool for Enhancing Spatial Visualization Skills in Apparel Design. Int. J. Technol. Des. Educ. 2011, 21, 505−517. (12) Carroll, J. B. Human Cognitive Abilities: A Survey of FactorAnalytic Studies; Cambridge University Press: New York, 1993. (13) Snow, R. E.; Lohman, D. F. In Implications of Cognitive Psychology for Educational Measurement; Linn, R., Ed.; Educational Measurement; Collier MacMillian: New York, NY, 1989; pp 263−331. (14) Hoffmann, R.; Laszlo, P. Representation in Chemistry. Angew. Chem., Int. Ed. 1991, 30, 1−16. (15) Habraken, C. L. Integrating into Chemistry Teaching Today’s Student’s Visuospatial Talents and Skills, and the Teaching of Today’s Chemistry’s Graphical Language. J. Sci. Educ. Technol. 2004, 13, 89− 94. (16) Gross, L.; Mohn, F.; Moll, N.; Liljeroth, P.; Meyer, G. The Chemical Structure of a Molecule Resolved by Atomic Force Microscopy. Science 2009, 325, 1110−1114. (17) Jones, L. L. Learning Chemistry through Design and Construction. UniServe Sci. News 1999, 3−7. (18) Dement, J. J. Chem. Eng. News 1967, 45, 7. (19) Gillespie, R. J.; Nyholm, R. S. Inorganic Stereochemistry. Q. Rev. 1957, 339−380. (20) Gillespie, R. J. The Valence-Shell Electron-Pair Repulsion (VSEPR) Theory of Directed Valency. J. Chem. Educ. 1963, 40, 295− 301. (21) Gillespie, R. J. Electron-Pair Repulsions and Molecular Shape. Angew. Chem., Int. Ed. 1967, 6, 819−830. (22) Gillespie, R. J. The Electron-Pair Replusion Model for Molecular Geometry. J. Chem. Educ. 1970, 47, 18−23. (23) Gilbert, J. L.; De Jong, O.; Justi, R.; Treagust, D. F.; Van Driel, J. H. Research and Development for the Future of Chemical Education. Chemical Education: Towards Research-Based Practice; Kluwer Academic Publishers: The Netherlands, 2002. (24) Jones, L. L.; Jordan, K. D.; Stillings, N. A. Molecular Visualization in Chemistry Education: The Role of Multidisciplinary Collaboration. Chem. Educ. Res. Pract. 2005, 6, 136−149. (25) Geldenhuys, W. J.; Hayes, M.; Van der Schyf, C. J.; Allen, D. D. Receptor Surface Models in the Classroom: Introducing Molecular Modeling to Students in a 3-D World. J. Chem. Educ. 2007, 84, 979− 982. (26) Kozma, R.; Russell, J. Multimedia and Understanding: Expert and Novice Responses to Different Representations of Chemical Phenomena. J. Res. Sci. Teach. 1997, 34, 949−968. (27) Kozma, R. B.; Chin, E.; Russell, J.; Marx, N. The Role of Representations and Tools in the Chemistry Laboratory and Their Implications for Chemistry Learning. J. Learn. Sci. 2000, 9, 105−144.

surroundings. All of these skills relate to learners’ spatial abilities, visualization strategies, and molecular representational competence, not their native language. This is promising in the context of the North American academic setting, where the first languages of student populations are becoming more diverse. Use of a touch-screen to manipulate “ball-and-stick” representations of molecules, similar to molecular modeling kits, is not restricted by language barriers. In the field of chemistry, where symbolic molecular representations are a language of their own, this is an advantage of touch-screen visual aids over written educational materials.

■

CONCLUSIONS

■

ASSOCIATED CONTENT

Touch-screen technology was found to positively influence development of students’ visual cognitive skills. With minimal instruction and less than 15 min use of the iPad, learners demonstrated enhanced matching skills relative to their peers using paper-based images as measured by their ability to match physical models to molecular images and match structural formulas to molecular images. Similarly, stronger construction skills were observed among those who used the iPad during earlier exercises based on their capacity to translate a structural formula into a physical model of their own creation, even though the iPad was not used during the construction exercise. Touch-screen tablets improve upon the functionality of desktop and laptop computers with their increased mobility and relative inexpensive nature; they make it possible to bring studentmanipulable computer images into the classroom. Thus, in accordance with Habraken’s view of an evolutionary chemical language,15 touch-screen devices will likely play an important role in how chemists learn and communicate in the future.

S Supporting Information *

Molecular structural data for the 11 generic VSEPR shapes. This material is available via the Internet at http://pubs.acs.org.

■

AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS This research was approved by the Mount Royal University Human Research Ethics Board. Financial support was provided by MRU. The iPad2 hardware is created by Apple, Inc. The iPad application “Molecules” from Sunset Lake Software is free to download from the iTunes app store.

■

REFERENCES

(1) Copolo, C.; Hounshell, P. B. Using Three-Dimensional Models to Teach Molecular Structures in High School Chemistry. J. Sci. Educ. Technol. 1995, 4, 295−305. (2) Kaberman, Z.; Dori, Y. J. Question Posing, Inquiry and Modeling Skills of Chemistry Students in the Case-Based Computerized Laboratory Environment. Int. J. Sci. Math. Educ. 2009, 7, 597−625. (3) Stieff, M.; Ryu, M.; Dixon, B.; Hegarty, M. The Role of Spatial Ability and Strategy Preference for Spatial Problem Solving in Organic Chemistry. J. Chem. Educ. 2012, 89, 854−859. G

dx.doi.org/10.1021/ed400674v | J. Chem. Educ. XXXX, XXX, XXX−XXX

Journal of Chemical Education

Article

(28) Wu, H. K.; Krajcik, J. S.; Soloway, E. Promoting Conceptual Understanding of Chemical Representations: Students’ Use of a Visualization Tool in the Classroom. J. Res. Sci. Teach. 2001, 38, 821− 842. (29) Nathan, M. J.; Stephens, A. C.; Masarik, D. K.; Alibali, M. W.; Koedinger, K. R. In Representational Fluency in Middle School: A Classroom Based Study; Mewborn, D., Szatajn, P., White, D., Wiegel, H., Bryant, R., Nooney, K., Eds.; Proceedings of the Twenty-fourth Annual Meeting of the North American Chapter of the International Group for the Psychology of Mathematics Education ERIC Clearinghouse for Science, Mathematics, and Environmental Education: Columbus, OH, 2002. (30) Ainsworth, S.; Bibby, P.; Wood, D. Examining the Effects of Different Multiple Representational Systems in Learning Primary Mathematics. J. Learn. Sci. 2002, 11, 25−61. (31) Harle, M.; Towns, M. A Review of Spatial Ability Literature, Its Connection to Chemistry, And Implications for Instruction. J. Chem. Educ. 2011, 88 (3), 351−360. (32) Appling, J. R.; Peake, L. C. Instructional Technology and Molecular Visualization. J. Sci. Educ. Technol. 2004, 13, 361−365. (33) Stieff, M. Improving Representational Competence Using Molecular Simulations Embedded in Inquiry Activities. J. Res. Sci. Teach. 2011, 48, 1137−1158. (34) Peters, M.; Battista, C. Applications of Mental Rotation Figures of the Shepard and Metzler Type and Description of a Mental Rotation Stimulus Library. Brain Cogn. 2008, 66 (3), 260−264. (35) Mann, H. B.; Whitney, D. R. On a Test of Whether One of Two Random Variables Is Stochastically Larger than the Other. Ann. Math. Stat. 1947, 18 (1), 50−60. (36) LarsonB.Sunset Lake Software Molecules, 2012. (37) Welch, B. L. The Generalization of “Student’s” Problem When Several Different Population Variances Are Involved. Biometrika 1947, 34, 28−35. (38) Fagerland, M. W.; Sandvik, L. Performance of Five Two-Sample Location Tests for Skewed Distributions with Unequal Variances. Contemp. Clin. Trials 2009, 30 (5), 490−496. (39) Fisher, R. A. On the Interpretation of χ2 from Contingency Tables, And the Calculation of P. J. R. Stat. Soc. 1922, 85, 87−94. (40) Agresti, A. A Survey of Exact Inference for Contingency Tables. Statist. Sci. 1992, 7, 131−153. (41) Geiser, C.; Lehmann, W.; Eid, M. A Note on Sex Differences in Mental Rotation in Different Age Groups. Intelligence 2008, 36, 556− 563. (42) Stull, A. T.; Hegarty, M.; Dixon, B.; Stieff, M. Representational Translation with Concrete Models in Organic Chemistry. Cogn. Instr. 2012, 30, 404−434. (43) Smith, L. B. Cognition as a Dynamic System: Principles from Embodiment. Dev. Rev. 2005, 25, 278−298. (44) Hambrick, D. Z.; Libarkin, J. C.; Petcovic, H. L.; Baker, K. M.; Elkins, J.; Callahan, C. N.; Turner, S. P.; Rench, T. A.; LaDue, N. D. A Test of the Circumvention-of-Limits Hypothesis in Scientific Problem Solving: The Case of Geological Bedrock Mapping. J. Exp. Psychol. Gen. 2012, 141, 397−403. (45) Hambrick, D.; Meinz, E. Limits on the Predictive Power of Domain-Specific Knowledge and Experience for Complex Cognition. Curr. Dir. Psychol. Sci. 2011, 20, 275−279. (46) Stieff, M. Mental Rotation and Diagrammatic Reasoning in Science. Learn. Instr. 2007, 17, 219−234. (47) Uttal, D. H.; Cohen, C. A. In Spatial Thinking and STEM Education: When, Why, and How?; Ross, B. H., Ed.; The Psychology of Learning and Motivation; Academic Press: New York, 2012; Vol. 57, pp 147−181. (48) Goldin-Meadow, S. When Gesture Does and Does Not Promote Learning. Lang. Cogn. 2010, 2, 1−19. (49) Goldin-Meadow, S. How Gesture Promotes Learning Throughout Childhood. Child Dev. Perspect. 2009, 3, 106−111. (50) Goldin-Meadow, S.; Nusbaum, H.; Kelly, S. D.; Wagner, S. Explaining Math: Gesturing Lightens the Load. Psychol. Sci. 2001, 12, 516−522.

(51) Goldin-Meadow, S.; Levine, S. C.; Zinchenko, E.; Yip, T. K.; Hemani, N.; Factor, L. Doing Gesture Promotes Learning a Mental Transformation Task Better than Seeing Gesture. Dev. Sci. 2012, 15, 876−884. (52) Göksun, T.; Goldin-Meadow, S.; Newcombe, N.; Shipley, T. Individual Differences in Mental Rotation: What Does Gesture Tell Us? Cogn. Process. 2013, 14, 153−162.

H

dx.doi.org/10.1021/ed400674v | J. Chem. Educ. XXXX, XXX, XXX−XXX