Research: Science and Education edited by
Chemical Education Research
Diane M. Bunce
Students’ Use of Web-Based Tutorial Materials and Their Understanding of Chemistry Concepts
The Catholic University of America Washington, D.C. 20064
William J. Donovan* and Mary B. Nakhleh Department of Chemistry, Purdue University, West Lafayette, IN 47907-1393; *
[email protected] Overview
discover how students perceive their understanding of chemistry concepts to be affected by the use of these WebMany chemical educators have turned to the World Wide based materials, and to discover in some measurable way how Web to supplement other resources available in their courses. understanding of chemical concepts differs between students While the Web is recognized as valuable for presenting inforwho use the Web-based materials and those who do not. Here mation, one of the downsides of storing what Paulisse and Polik we present the findings of the initial phase of this study. called a “static document” (1) is that the same information could The Web site, entitled “Visualization and Problem Solving be presented just as easily and with little pedagogical difference for General Chemistry” (2), includes tutorial materials in traditional hard-copy format. featuring the types of representations mentioned above and John Nash and William Robinson of Purdue University covering the topics of Liquids, VSEPR, Coordination have developed Web-based tutorial materials for five general Compounds, Vibrational Modes, and the Molecule Library. chemistry topics. The materials include static, animated, and The Molecule Library includes an index of molecules and ions user-manipulable representations of molecules and chemical and offers the user a static Lewis dot structure, a manipulable processes. These representations would appear to offer advanball-and-stick model, and the formula, the name, and an audio tages over paper representations of the same concepts because file of the name of the molecule being spoken. The Vibrational of their ability to show motion and to allow the student to Modes page, first available in January 2000, is the most recent manipulate the representation. Our research was designed to addition. A section of the Web site entitled “How Do I Solve It?” includes step-by-step descriptions of how to solve common types of problems in general chemistry. Table 1. Strongest Responses to Scaled-Response Questions Other sections offer tutorials on common operations Mean Statement in Microsoft Excel and Hyperchem. Our study focuses Response on the sections of the site that specifically deal with CHM 126, Spring 1999 ( N = 32) chemistry content and offer the various types of repThe CHM 115-116 Help Page helped me understand the material better. 2.00 resentations, namely the Liquids, VSEPR, CoordiThe Web site provided a new way to understand chemistry. 2.17 nation Compounds, and Molecule Library pages. I liked using the Web site because it allowed me to work at my own pace.
2.17
Navigating the Web site was confusing for me.
4.00
Using the Web site was easy.
2.04
The Web site did NOT help me to understand chemistry concepts.
4.10
I would rather NOT use the Web site to learn chemistry.
3.86
Using the Coordination Compounds Page was useful to me.
2.10
Using the Microsoft Excel tutorial materials was useful to me.
2.00
Using the Common Operations in Hyperchem Page was useful to me.
1.81
CHM 124, Spring 1999 ( N = 40) Navigating the Web site was confusing for me.
4.00
Using the Web site was easy.
1.95
I would rather not use the Web site to learn chemistry.
3.45
CHM 116, Spring 1999 ( N = 139) Using the Web site was easy.
2.66
CHM 115, Spring 1999 ( N = 218) Navigating the Web site was confusing for me.
3.65
The Web site did not help me to understand chemistry concepts.
3.42
I would rather not use the Web site to learn chemistry.
3.57
CHM 115, Fall 1999 ( N = 242) I liked using the Web site because it allowed me to work at my own pace.
2.41
Using the VSEPR Page was useful to me.
2.59
I used the molecular representations that could be manipulated by the user with the mouse.
2.55
N OTE: Questions were rated on a scale of 1 (strongly agree) to 5 (strongly disagree).
Study Design Students in CHM 115, 116, 124, and 126 in Spring 1999 and CHM 115 in Fall 1999 at Purdue were surveyed about their use of the Web-based materials. The survey included demographic, scaledresponse, and free-response questions. CHM 115– 116 is the general chemistry sequence for aspiring engineers. CHM 124 is the second semester of a more rigorous general chemistry sequence for engineers. CHM 126 is the second-semester general chemistry course for chemistry majors. Students in CHM 115 were advised about the VSEPR page by their instructor during the coverage of the topic. Students in CHM 124 were advised of the availability of all the tutorial pages available. Students in CHM 116 were advised of the Coordination Compounds Page by their instructor and the researcher. Students in CHM 126 were given a homework assignment, prepared by the instructor, about coordination compounds. This assignment involved using the Coordination Compounds Page. Volunteer students in CHM 126 were individually interviewed about their use of the Web site and
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Research: Science and Education Table 2. Statistically Significant Differences in Responses to Scaled-Response Questions, by Gender Mean Response
Statement
Female
Male
p
CHM 126, Spring 1999 (F = 18, M = 14) Navigating the Web site was confusing for me.
4.24
3.33
.024
The Web site did not help me to understand chemistry concepts.
4.25
3.60
.031
Using the VSEPR page was useful to me.
2.20
3.00
.005
Using the Liquids page was useful to me.
2.22
3.00
.004
If I were to take another chemistry course, I would use this page to review some material.
1.50
2.81
.004
The Web site provided a new way to understand chemistry.
1.50
3.08
.002
I would rather not use the Web site to learn chemistry.
4.50
3.18
.007
The CHM 115–116 Help Page helped me understand the material better.a
2.47
2.94
.008
I liked using the Web site because it allowed me to work at my own pace.
2.62
2.92
.039
Navigating the Web site was confusing for me.
3.56
3.14
.020
The Web site did not help me to understand chemistry concepts.
3.38
2.92
.042
I enjoyed using the Web site materials.
2.71
2.97
.042
Using the VSEPR Page was helpful to me.
2.43
2.91
.011
If I were to take another chemistry course, I would use this page to review some material.
2.20
2.56
.002
The Web site allowed me to learn concepts that would be difficult to understand otherwise.
2.52
2.77
.014
Using the VSEPR Page was useful to me.
2.40
2.69
.006
I used the Visualization and Problem Solving Page because I needed help with the material.
2.60
2.86
.025
CHM 124, Spring 1999 (F = 11, M = 26)
CHM 116, Spring 1999 (F = 54, M = 81)
CHM 115, Fall 1999 (F = 85, M = 157)
N OTE: Questions were rated on a scale of 1 (strongly agree) to 5 (strongly disagree). aBefore Fall 1999, the Web page was known as the Chemistry 115–116 Help Page, and the questions referred to this name.
their understanding of certain coordination chemistry concepts. This class was selected for interviews because the Web site was part of an assignment and the probability of finding students who had used the site was likely to be greater than in other courses. During the interview, each student was also asked to draw a concept map involving several specified coordination chemistry terms. The researcher closed the interview by allowing the student to ask questions about the research or give any additional thoughts. Data Analysis and Results
Surveys Scaled-Response Statements Responses to the scaled-response survey questions were frequency-counted and the mean student response was calculated. Responses were scaled from 1 (strongly agree) to 5 (strongly disagree). A sixth option, “did not use”, was also offered so that we could distinguish students who genuinely felt neutral about a statement from students who had no opinion because they did not use the Web site. Responses indicating this sixth option did not enter into the calculation of the means for the scaled-response questions. The strongest responses to the scaled-response survey questions are shown in Table 1. 976
Statistically, very significant differences between genders were observed for responses to several of the scaled-response questions (Table 2). In each case where a statistically significant difference existed between the female and male responses, the mean female response was more positive toward Web site use (i.e., stronger agreement with positive statements such as “I liked using the Web page because it allowed me to work at my own pace” and stronger disagreement with negative statements such as “I would rather not use the Web to learn chemistry”). This is a very interesting and potentially important finding. A previous study of use of computers in biology laboratories (3, 4), found a similar result: in each case where a gender difference existed, women responded more favorably about computer use than men. In a study of secondary students’ use of instrumentation (Malina, E. G.; Nakhleh, M. B.; Burnett, D. W. School Sci. Math., manuscript submitted), all but one of the gender differences showed that girls were more positive about use of instrumentation. We did not check for such gender differences in our previous study of student Web site use (5). This congruence of opinion about instrumentation, computers, and the Web is certainly consistent and interesting. It presents interesting possibilities for how such materials might be used to improve science courses for women. The availability of computers and Web-based tutorial materials might be a posi-
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tive aspect of a science course for women, and this is an area in which further research would be useful.
Table 3. Frequency of Representative Coding Categories for Free-Response Survey Questions, All Courses Coding Category
Frequency
Illustrative Response
Free-Response Questions Why did you choose to use the Visualization and Problem Solving Web Page? a ( N = 188 coded statements) The free-response survey questions were coded by Materials/Information 41.(22%) Get more info on topics when I didn’t an open coding scheme in which codes were generated have time to go to the TAs. by examination and analysis of the data. New codI needed help/was confused 36.(19%) I was having trouble with Chem. 115 so I ing categories were opened as necessary. This condecided to try the Web page out. trasts with a coding scheme in which all responses To get better understanding 9.(5%) Because I thought they would improve my understanding of chemistry. are coded against predetermined categories. In toHow did using the Visualization and Problem Solving Page affect your understanding tal, 29 codes, some with subcategories, were opened. of the material? Please give specific examples. ( N = 167) Data from all courses surveyed were transcribed, Representations/visualization/ 28.(17%) Using the Web site better helped me to coded, and tabulated. Table 3 presents the highest animations visualize these shaped in 3D rather frequencies of coding categories for responses to than trying to picture them in my head. the free-response questions. For example, 188 reIt helped (nonspecific) 39.(23%) It helped. sponses to the question “Why did you choose to use Which parts of the Visualization and Problem Solving Page were most helpful to you, and which were the least useful to you? Please explain your answer. ( N = 131) the Visualization and Problem Solving Web Page?” VSEPR 24.(18%) VSEPR, because it helped me understand were assigned to coding categories (multiple codes the material. for one response were allowed if appropriate). Of Coordination Compounds 15.(11%) The coordination compounds page was these 188 statements, 41 were coded in the Materithe most helpful because the lecture als/Information category. given on that topic weren’t clear. Patterns arose in student responses to the freeAll parts were helpful 10.(8%) Everything was pretty useful. response survey questions. Students who used the Web Why did you not use the Visualization and Problem Solving Page? ( N = 441) page in general believed that they needed help with 278.(63%) At first I was not aware that this page Didn’t know about it/forgot about it was available, and then I forgot that it the chemistry material or visited the site to gain acwas available. cess to information. One student’s response to “Why Did not need to use it 91.(21%) I felt like I knew the material well enough did you choose to use the Web page?” provides an not to use the Web site. excellent example of a statement that fits the Access problems 18.(4%) I don’t have a computer in my room + the “Needed help” coding category: “I was having lines are so long in the labs. trouble with Chem. 115 so I decided to try the Web No time/other things to do 15.(3%) I didn’t find that I had much time to view the site. page out.” An example quote from the free-response Can use book/prefer book 15.(3%) Easier to open book/flip to index. survey data is given with each coding category in How do you think that using Web-based materials would have affected your Table 3. understanding of chemistry? ( N = 416) Overall, the Web site users stated that they used Might/would have helped 239.(57%) It would have helped me understand the Web page to obtain help and chemistry informachemistry better. tion. Some students believed that using the materials Might/would have had no 94.(23%) I don’t think it would have had much effect effect. on the Web site helped in visualization of chemical Representations/visualization 20.(5%) Easier to visualize 3-D models. phenomena or provided examples, but others felt that How do you feel about using the Web to learn chemistry in CHM 115–116? the Web page made no difference in their understand( N = 205); CHM 115 Fall 1999 only ing. Web site users believed in general that the part of Good idea 90.(44%) I feel that it is a good idea and would be the Web site pertaining directly to the chemistry covbeneficial for students. ered in class was most useful (VSEPR for CHM 115; Will use it in the future 19.(9%) I will try to use it in chem 116. Coordination Compounds for CHM 116 and 126). Bad idea/not a good idea 14.(7%) I do not feel the Web is a good way. Most students who did not use the Web site stated More exposure/different ways 14.(7%) I feel it is helpful and gives an alternative that they did not use it because they had forgotten to learn to learning rather than just reading the about it or did not know about it at all. Some stated material. aBefore Fall 1999, the Web page was known as the Chemistry 115–116 Help that they did not use the Web site because they did not need to use it. Generally, however, nonusers be- Page, and the questions referred to this name. lieved that using the Web site might have helped their understanding of chemistry concepts, through visualization professor had assigned homework (not collected or graded) based tools or reinforcement of lectures, or as a resource to study on the Web site materials, which increased the likelihood of from. Even nonusers had positive feelings about using the Web finding students who had used the site. The population of CHM to learn chemistry. 126 is fairly homogeneous owing to the students’ common major and similar backgrounds: all students in the course had Interviews passed a math placement test and taken high school chemistry. With the survey we were able to gain a broad underThe majority of them were second-semester freshmen. standing of how students used the Web-based materials and Both Web site users and nonusers were solicited and six how they felt about using them. To gain deeper insight into students were interviewed. This represents 12% of the class in students’ Web site use and understanding of chemical conSpring 1999. The volunteers were guaranteed anonymity and cepts, we solicited volunteers from CHM 126 in Spring 1999 were assigned pseudonyms for the transcription and data analyfor individual interviews. This course was chosen because the sis. 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Research: Science and Education Table 4. Responses to Coordination Chemistr y Inter view Questions
Table 5. Correctness of Concept Map Links
No. of Responses by Response
Web Site Usersa
Web Site Nonusersa
No. of Links Drawn by Link
Incorrect
4
3
Incorrect
Incomplete
6
3
Incomplete
21
25
Correct
Correct
Web Site Users a
Web Site Nonusers a
2 (5%)
0 (0%)
8 (21%)
0 (0%)
28 (74%)
26 (100%)
aData represent responses by 3 users and 3 nonusers.
aData represent links drawn by 3 users and 3 nonusers.
tween Web site users and nonusers because Web site use was entirely voluntary. We were not attempting to compare equivalent groups of students; we were interested in how students who had used or not used the materials on the Web site understood chemistry and why students decided to use or not use the site. This small group provided a great deal of data that suggest interesting trends; these will be investigated in phase 2 of our study, which will involve more students. In the interview, the interviewer discussed with the students the nature of their use of the Web site or the reasons for their not using the site. Students were asked to discuss their thoughts about using the Web in their specific course as well as in chemistry courses in general. They were then asked some directed questions about coordination chemistry and were asked to draw a concept map of some coordination chemistry terms. This topic was chosen because the course instructor had given homework about coordination chemistry that involved using the Web site.
a base” would be an example of an incomplete statement. In some cases water does act as a base, but in others it can act as an acid. Victor’s statements concerning ammonia and oxalate ion as ligands demonstrates a statement categorized as incomplete.
Discussion of Coordination Chemistry The questions about coordination chemistry dealt with shapes of coordination complexes, isomerism, and ligands. Students’ responses were judged as correct, incorrect, or incomplete. Mark’s statements concerning ammonium ion as a ligand are an example of what would be judged as correct. INTERVIEWER: Could NH4+ act as a ligand in a coordination compound? MARK: I don’t think so, no. INTERVIEWER: OK, and why is that? MARK: Because it doesn’t have any electrons to give.
Chad’s discussion of the relationship between the representations of two square planar complexes (which cannot have optical isomerism) represents an incorrect statement. INTERVIEWER: I was wondering if you think that is a pair of isomers. CHAD: They’d be optical isomers, because this guy is the mirror image of this one, obviously, but then this one isn’t going to match up.
In reality, the two complexes presented to the students were identical. As Chad observed, one was indeed the mirror image of the other. Chad’s response to this question was categorized as incorrect, however, because the complexes represented were not isomers; one representation could be rotated 180° so as to be identical to the other. A statement was judged to be incomplete if it contained information that could be correct in some cases but not in others, or if it had both correct and incorrect aspects. “Water is
978
INTERVIEWER: Why the difference between ammonia being monodentate and oxalate being bidentate? VICTOR: Because with this one, you have the negative charges. I think they’re on these oxygens? INTERVIEWER: The single-bonded ones? I just want to be sure I have it on the tape. VICTOR: I think it’s the single bond. I’m not actually sure. Maybe it’s [the points of attachment from oxalate to metal ion] on the double-bonded. It’s between two of these oxygens, and since they both have extra negative charge, they could clamp on to a metal ion, transition ion. But with ammonia, there’s only going to be one pair of extra electrons on the nitrogen, and that can only bond once with a ligand. And there’s no way geometrically for it to clamp on to it.
Victor made some correct statements in his discussion, such as the idea that monodentate ligands (ammonia) attach to the metal ion once and bidentate ligands (oxalate ion) attach in two locations, and the idea about the geometry of the ligands; but he also had some incorrect notions, such as that the charge on the oxygen explains why the oxalate ion is a bidentate ligand. A second rater judged a random sample of half of the student responses, assigning a score of 1 to agreement between the raters and 0 to disagreement. These scores were summed and the fraction of agreements was calculated as an inter-rater reliability. Overall, the raters agreed on 28 of 31 responses; the disagreements were between “incorrect” and “incomplete” categories. This represents an inter-rater reliability of 28/31 or 0.90. Students were asked 31 questions about coordination chemistry. The scoring of their responses is shown in Table 4. There were no statistically significant differences between Web site users and nonusers. This portion of the interview has been revised for future use, to better discern whether differences exist between users’ and nonusers’ understanding of coordination chemistry. Concept Maps Students were asked to draw a concept map of some coordination chemistry concepts. They were given a brief description of concept mapping, shown two example maps of the concept of density, and given a list of terms that included coordination complex, coordinate covalent bond, ligand, donor atom,
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atta che s to
nt ai n
with different
co
Lewis acid
central atom
s
acts as a
donor atom(s) s te na do
isomers
has
of ir pa
coordination complex accepts pair of
coordinate covalent bond
bidentate
is
con tain s
ligand
is ac
ts
for m
as
sa
monodentate
Lewis base electrons
donates pair of
Figure 1. Beth’s concept map.
electron, isomers, Lewis base, Lewis acid, central atom, monodentate, and bidentate. They were told that they could add terms or not use a term as needed. They were instructed to make the map as connected as they felt necessary, to write linking words between concepts, and to show directionality between concepts. An example of a concept map drawn by Beth, a Web site user, is shown in Figure 1. Note that Beth made a compound link in her map by drawing an arrow through one concept to the next: “Coordination complex has isomers with different donor atoms.” Beth’s concept map links were all judged to be correct or complete. Judging of the concept maps was similar to judging the interview discussion of coordination chemistry. Each concept link was judged as correct, incorrect, or incomplete. The interrater reliability was 0.94, which was deemed acceptable. Table 5 shows the totals of the concept links judged. Students who did not use the Web site made no concept map links that were judged incorrect or incomplete. Students who did use the site had about the same number of correct links as the nonusers, but they made more links overall and some of these links were judged incorrect or incomplete. This suggests that the students who used the Web site created more knowledge, but some of that knowledge was not correct. To account for the different numbers of links made by the students, the percentages of correct, incomplete, and incorrect links were calculated for each student. The higher percentage of correct links for Web site nonusers almost reaches statistical significance at the 95% level ( p = .07). The percentage of incomplete links was significantly larger (p = .04) for users than for nonusers. The percentage of incorrect links did not differ significantly between groups. The larger number of links attempted by Web site users may be related to the motivation factor between the groups (see below). Results from the chemistry discussion and concept map portions of the interview suggest that the students who did not use the Web site had a better understanding of coordination chemistry than the students who did use the site and are consistent with the statements made by some students on the free-response survey questions. Many students who did not use the Web site felt that they did not need to use it because they understood the material well enough already. This is also consistent with our past research on Web site use
(6 ), which found that students who used an organic chemistry Web site did not understand the relevant chemistry concepts as well as students who did not use the site. We speculated that the Web site might be more attractive to students who need more help with chemistry. The concept map and survey results of this study are consistent with that speculation. We acknowledge that the sample of students interviewed was limited. In phase 2 of this study, we will expand the number of students interviewed and modify our research instruments so as to gain more insight from more students on how they understand chemistry concepts and how Web site use may be related to this understanding. Visualization Theme The dominant trends in the discussion of the Web site agree well with the survey responses. The use of representations and visualization on the Web was a strong point for the students interviewed. Leo, a site user, referred to the usermanipulable 3-D representations of molecules on the Web site: “It’s really nice to have that page where the molecules spinning around. You know, you drag the mouse on them and they turn around.” Beth, another user, described her thoughts about the representations of coordination complexes: “Well, this one [Web site] in particular, like I said, helped to visualize it. If you don’t have a 3-D model, it’s hard to see a coordination compound, how it all fits together.” The issue of materials and information was important to site user Victor: “It’s better than just going through lecture again because you actually get to focus more energy and time on things you don’t understand and you can skip over the things that you do.” Motivation Theme Not all comments about using the Web to learn chemistry were positive, however. Leo echoed the sentiments of some students’ survey responses in terms of using the Web site to review or study. When asked why he used the Web site, Leo said: “It was given to us as part of a homework assignment, and I try to get the homework done because I’m afraid not to because something might be on the test.” The interviewer asked, “If it weren’t part of the homework, would you have used it, do you think?” Leo replied, “Probably not. I probably wouldn’t have even looked at it.” Access Theme Martha, a Web site nonuser, stated a two-pronged concern about computer access: access to the Web itself, and accessing the representations of the molecules in the Web browser. “I don’t really like walking at night to a [computer] lab. … I couldn’t get the pictures. On the worksheet, it said to draw the structure. On my computer, it had a little square, and then it had a little puzzle piece. … I couldn’t figure out a way to get to them.” Encountering this difficulty, Martha gave up on doing the assignment on the Web. (Martha’s problem with the puzzle piece on the screen was that the Chime plugin (6 ) was not installed on her computer. Purdue’s lab computers have this software, but individuals would have to download it to see the structures on their own computers.) Discussion The chemistry understanding (as determined from the chemistry discussion and concept map portions of the interview) of students who did not use the tutorial Web site was
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determined to be more complete than that of students who did use the Web site. This is consistent with our past findings (5). We speculate that it is the result of weaker students being attracted to the Web site as a supplementary source of help. Leo’s statements about using the Web site only because it was required in a homework assignment, not because he wanted to use it, reflects this sentiment. The reasons for Web site use given by students in the free-response survey support this speculation as well: accessing materials and information, needing help, and the intent to gain a better understanding of chemistry are all characteristic of students who want to use the Web site to help themselves. Students who felt they already had sufficient understanding of chemistry would not give such reasons for using the Web site. The primary reason given by students for not using the Web was that they did not know about the site or forgot about it. This is unfortunate, since the instructors for the courses involved in this study mentioned the Web site and suggested it as a source of help. In all courses except the Spring 1999 offering of CHM 115, links were available from the course Web page to the tutorial Web site. Of course, if students are not inclined to use the Web, they would not find these links. Some students stated that they did not use the Web site because they did not need to use it. This was the type of student we encountered as a Web site nonuser in our previous study (6 ). A tutorial Web site may not be attractive to students who feel they have already mastered the material. A possible third type of nonusers may feel that the Web site is not a match for them. One student in CHM 115 in Fall 1999 responded to the question “How do you feel about using the Web to learn chemistry in CHM 115–116?” as follows: “I don’t think it would have been useful for me, but it might have been for someone else.” This acknowledgment of different types of resources being useful or appropriate for different students is appropriate for all of us to remember as new technologies for teaching and learning are developed and implemented. Implications for Teaching This study’s findings with regard to gender differences in attitudes toward Web site use may be important to those who are concerned about women in science classes. The findings are consistent with those of past research at Purdue involving computers in science classes (3). The favorable attitudes toward computer and Web site use held by women in these studies
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suggest that availability of computers and the Web may be a valuable aspect of a science course for women. The primary reason students gave for not using the Web site was that they did not know about it or forgot about it. This is unfortunate but is a very real problem. Among students who did know about the Web site, the majority who chose not to use it stated that they did not need it to learn chemistry. Therefore, it seems reasonable to recommend that instructors assign the Web site as part of homework or other assignments, so all students have the opportunity to use it and see for themselves if it would help them. Some students found that using the Web site benefited them. In particular, the site appears to be useful for students who wish to visualize the chemistry involved. According to the students, the multimedia and visual aspects of the Web site help them to understand chemistry. Therefore, it may be beneficial for the instructor to employ these Web-based representations in class when covering relevant material. We recommend that these findings be taken into consideration in the design and implementation of Web-based materials for chemistry courses. Acknowledgments We gratefully acknowledge the three anonymous reviewers for their valuable comments in the preparation of this manuscript. We also thank the faculty, staff, and students of the courses involved and the General Chemistry Office staff at Purdue for their cooperation in our study. Literature Cited 1. Paulisse, K. W.; Polik, W. F. J. Chem. Educ. 1999, 76, 704. 2. Visualization and Problem Solving for General Chemistry; http://www.chem.purdue.edu/gchelp/ (accessed Mar 2001). 3. Eichinger, D. C.; Nakhleh, M. B.; Auberry, D. L. Presented at the 1997 Annual Meeting of the National Association for Research in Science Teaching, Oak Brook, Ill. ERIC document ED406174. 4. Eichinger, D. C.; Nakhleh, M. B.; Auberry, D. L. J. Comput. Math. Sci. Teach. 2000, 19, 253–276. 5. Nakhleh, M. B.; Donovan, W. J.; Parrill, A. L. J. Comput. Math. Sci. Teach. 2000, 19, 355–378. 6. MDL Chime Plugin for Netscape and Internet Explorer; http:// www.mdli.com (accessed Mar 2001).
Journal of Chemical Education • Vol. 78 No. 7 July 2001 • JChemEd.chem.wisc.edu