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Teaching with Technology
Gabriela C. Weaver Purdue University West Lafayette, IN 47907
Interdisciplinary, Application-Oriented Tutorials: Design, Implementation, and Evaluation
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Carolyn Herman, Rachel E. Casiday, Roberta K. Deppe,† Michelle Gilbertson, William M. Spees, Dewey Holten, and Regina F. Frey* Department of Chemistry, Washington University, St. Louis, MO 63130; *
[email protected] Many students in introductory chemistry sequences are interested in a variety of fields such as biology, physics, engineering, and medicine. At this stage of their education, these students often do not see the importance of chemistry in their field of interest (1–4), and many students (5, 6) and faculty (7) indicate the need for materials that elucidate the connection between course content and real-world applications. At Washington University, we wanted to increase students’ interest in learning chemistry by increasing their awareness of chemistry’s importance, especially in their everyday lives. We also wanted to improve their ability to solve interdisciplinary problems through qualitative and quantitative reasoning and to integrate knowledge from a variety of sources. Finally, we wished to reinforce fundamental chemical concepts. We addressed these goals through the development of new laboratory materials that are rich in interdisciplinary applications and contain resources (animations and interactive viewing of molecular models) to help students visualize molecules and their interactions. We believe the interdisciplinary applications help students perceive how chemistry is important in the world around them. Interdisciplinary and real-world problems also can train students to decipher important chemical information from complex, multifaceted sets of data. Visualization tools help students develop better mental models for molecules and molecular behavior (8). Collectively, the goals of our approach are to teach the students to see the relevance of chemistry in the macroscopic world around them, teach them to incorporate information from multiple sources, and better equip them to think analytically in solving problems relating microscopic structure and dynamics to macroscopic properties. From 1998 to 2000, fifteen application-oriented chemical tutorials were developed and thirteen are currently in use in our general chemistry laboratory curriculum. The tutorials are Web based (9) and each tutorial accompanies an experiment, where the key concepts of each tutorial complement the key concepts in the corresponding experiment. The Web-based character of the tutorials allows students flexibility in scheduling their work on the tutorial assignments and allows them to take advantage of many of the molecular visualization techniques enabled by computer technology (10). Each tutorial is self-contained; however, the tutorials also build on one another so that students are reminded of pertinent concepts and examples from previous tutorials. The students must answer questions about each tu† Current address: Department of Psychology, Oglethorpe University, Atlanta, GA 30319.
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torial (concerning both the chemical concepts and the application) and the tutorial questions are worth 20% of the grade for each experiment. Student evaluations of the tutorials were given at the end of each semester during the tutorial development and were used to refine the application-oriented tutorials. In fall 2000, we performed a detailed statistical evaluation of the tutorials used during that semester. The results of this evaluation validate the positive impact of the interdisciplinary and microscopic approaches that were used throughout our curriculum development. The tutorials are written for an honors-level general chemistry course; however, they allow for flexibility of use with a range of students. By adapting the questions and providing some additional background material to meet the needs of a particular group of students, instructors can use the tutorials in many settings to improve students’ problemsolving abilities and increase their awareness of chemistry in the world around them. The tutorials have been used with groups as diverse as high-school students and graduate-level pharmacy students. In the first section of this article, the general features of the Web-based tutorials are described. In the second section, the statistical evaluation study performed in fall 2000 is presented. The third section contains results from this study and the final section contains discussion and conclusions related to our application-oriented tutorial project. Description of the Tutorials
Overview The titles of the thirteen tutorials currently used in our program and the key concepts explored in these tutorials are listed in Tables 1 and 2. The tutorials can be separated into eight biological applications (Table 1) and five engineering– environmental applications (Table 2). Each tutorial begins with a list of the key chemical and application-oriented concepts to be explored. This list highlights for the students the concepts they should focus on as they study the tutorial. Animation, molecular coordinates for interactive viewing, and tutorial-page links are also noted in this list. The body of the tutorial begins by introducing how the topic of the tutorial relates to the students’ everyday lives. Then the dependence of the topic on specific concepts is shown and the necessity of studying these concepts for a deeper understanding of the application is emphasized. Hence, key chemical concepts (and any other necessary ideas) are taught in the context of the application. Discussion ques-
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tions are also interspersed throughout each tutorial to help the students clarify their understanding of the application and the underlying chemistry. The tutorial ends by linking the key chemical concepts, the key application concepts, and the application storyline together in a summary. In addition, references and Web links that are related to the application are included, which allow interested students to research the topic in greater depth. All of the tutorials reference each other via Web links as appropriate. This referencing reinforces concepts that are learned in multiple tutorials, develops recurring themes, and helps students with integrating a range of ideas. One tightly linked set of tutorials is the blood-chemistry tutorials (the first four tutorials listed in Table 1), which deal with key chemical processes in blood (11).
Special Features The tutorials incorporate several special features of computer technology that enhance the students’ understanding and appreciation of chemistry and develop their problemsolving skills by drawing together information from different sources. These features are three-dimensional representations of compounds, interactive molecular viewing, connection of microscopic structure and dynamics to macroscopic properties, and use of questions that require integration of knowledge from the tutorial, lab, and lecture. Computer-generated, three-dimensional molecular representations are included throughout the tutorials. These representations help students to visualize three-dimensional structures of molecules; the students learn to use a variety of graphical representations and thereby gain different informa-
Table 1. Biological Tutorials and Key Concepts Tutorial
Key Concepts
Hemoglobin and the Heme Group: Metal Complexes in the Blood for Oxygen Transport
Metal complexes Spectroscopy and the color of blood
Iron Use and Storage in the Body: Ferritin and Molecular Representations
Polarity and molecular shape Graphical molecular representations
Maintaining the Body's Chemistry: Dialysis in the Kidneys
Membranes and ion channels Polarity Diffusion and concentration gradients
Blood, Sweat, and Buffers: pH Regulation during Exercise
Acid–base equilibria and equilibrium constants Quantitative and qualitative descriptions of buffers Le Châtelier's principle
Drug Strategies to Target HIV
Biological catalysts Enzyme kinetics Enzyme inhibitors
Energy for the Body: Oxidative Phosphorylation
Free energy and coupled reactions Free energy and reduction potentials Proton gradients
I Have Seen the Light! Vision and Light-Induced Molecular Changes
Isomerization of retinal and protein-conformational changes Absorption spectroscopy and MO theory
Nutrients and Solubility
Molecular basis for solubility: polarity of solvent and solute Mand thermodynamics of dissolution Quantitative measures of solubility
Table 2. Engineering and Environmental Tutorials and Key Concepts Tutorial
Key Concepts
Bonds, Bands, and Doping: How Do LEDs Work?
Bonding in elemental solids Bands and the conductivity properties of the elements Light-emitting diodes
Gas Laws Save Lives: The Chemistry behind Airbags
Ideal-gas law (macroscopic picture) Kinetic theory of gases (microscopic picture)
Improving Air Quality with Electric Vehicles
Oxidation and reduction Simple reaction mechanisms Batteries, lead acid and flow
Phase Changes and Refrigeration: Thermochemistry of Heat Engines
Phases of matter and phase transitions: microscopic and Mmacroscopic views Refrigeration cycle
Treating the Public Water Supply: What Is in Your Water, and How Is It Made Safe To Drink?
Solvation process in aqueous solutions. Suspensions and physical separation techniques Precipitation and ion-exchange
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tion about the molecule of interest (8). Two-dimensional representations are also included to encourage students to develop structural intuition and to visualize the conversion between two-dimensional and three-dimensional graphical pictures. One such example of this approach is illustrated in Figure 1 taken from the “I Have Seen the Light! Vision and Light-Induced Molecular Changes” tutorial. Whenever the structure of a molecule is shown, students may download the molecular coordinates (in pdb format) and view the molecule using an interactive molecular-viewing program such as Chime (12) or Rasmol (13). These interactive-viewing programs allow students to rotate molecules and to alternate between different types of graphical representations. To encourage students to take advantage of this feature, students are required to use these programs to answer questions and to submit printouts from the programs. The “Iron Use and Storage in the Body: Ferritin and Molecular Representations” tutorial is written specifically to emphasize different molecular representations and to elucidate the type of information each representation provides to the overall understanding of a molecular structure. Connecting microscopic structure and dynamics to macroscopic properties or observations is often nontrivial for students. This ability is particularly important in understanding interdisciplinary applications and in developing an appreciation of the everyday importance of chemistry. For example, for students to appreciate the use of chemistry in biological applications, it is important for them to understand the relationship between chemical and physiological views of the application. The tutorials contain illustrations that combine microscopic and macroscopic viewpoints of the same phenomena in order to demonstrate how such con-
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nections are made. An example is the phenomenon of blood– gas exchange in the tutorial entitled “Hemoglobin and the Heme Group: Metal Complexes in the Blood for Oxygen Transport” (11). At Washington University, each student’s performance on the tutorials is scored by grading of homework questions, given on the course Web page, which are different from the discussion questions given in the tutorials. To answer these homework questions, students must draw on information contained in the tutorials and on knowledge that they are expected to have from the laboratory and lecture components of their general chemistry courses. Evaluation of Study Design and Methods
Overview A pretest–posttest format was used for the statistical evaluation of the tutorials, with both an experimental group (Washington University) and a control group. The control group was a general chemistry laboratory course at a university that has comparable admissions selectivity and national reputation. The evaluation was performed in fall 2000. During that semester, the laboratory and lecture were separate courses at both schools, which was the typical arrangement. The topics covered in the laboratory and lecture classes at both schools were quite similar. General chemistry courses at both schools used some type of Web-based computer assignments. The Washington University laboratory curriculum consisted of six laboratory-based experiments of four hours each, which were conducted every other week. Each experiment had an associated Web-based application-oriented tutorial and related homework set, which was assigned in the alternate week. The six experiments and Web-based tutorial
Figure 1. Taken from the interdisciplinary online tutorial entitled “I Have Seen the Light! Vision and Light-Induced Molecular Changes”, the tutorial demonstrates the quantum chemical and spectroscopic underpinnings of vision and the chemical processes that are responsible for transducing the absorption of a photon into a physiologic sensation.
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Table 3. Fall 2000 Laboratory Assignments at Washington University Experiment and Associated Tutorial
Experiment Activities
Periodic Properties Bonds, Bands, and Doping: How Do LEDs Work?
Observe properties of elements and compounds Relate properties to periodic table position
Inorganic Reactions in Aqueous Solution Treating the Public Water Supply: What Is in Your Water and How Is It Made Safe to Drink?
Deduce the composition of unknown solutions Mby observing reactivities Perform flame tests
Inorganic Synthesis: Preparation, Purification, and Spectroscopy of Complex Ions Hemoglobin and the Heme Group: Metal Complexes in the Blood for Oxygen Transport
Synthesize inorganic coordination compounds Study the synthesized complexes with spectroscopy
Iron in Biology: Iron Content in Ferritin, the Iron Storage Protein Iron Use and Storage in the Body: Ferritin and Molecular Representations
Use spectrophotometry for trace analysis of iron
Stoichiometry and the Gas Constant Gas Laws Save Lives: The Chemistry Behind Airbags
Determine the value of the gas constant Determine the composition of an unknown mixture of an inert salt and an oxygen-producing substance
Spectroscopy and Quantum Chemistry of Dye Molecules I Have Seen the Light! Vision and Light-Induced Molecular Changes
Apply “particle-in-a-box” model to measured absorpMtion spectra of conjugated dye molecules
assignments are listed in Table 3. At the control school, the laboratory curriculum consisted of eleven experiments with one experiment performed per week. The control school’s laboratory curriculum did not contain an integration of interdisciplinary, application-oriented material as employed with the experimental group, nor were Web-based assignments used in the laboratory course. The Web-based assignments at the control school were different from those used by the experimental group and were administered in the lecture course and consisted of Web-based chapter-review quizzes. The pretest and posttest surveys consisted of questions about student characteristics and attitudes or confidence as well as chemical-content questions. The 12-question multiple-choice section covering chemistry principles taught in the laboratory courses at both schools was designed to measure the students’ abilities. This chemical-principles section contained both application-style and more traditional-style questions. Copies of the instruments can be found in the Supplemental Material.W Approval by the Human Studies Committees at both schools was received for this study. In addition, all students were informed at the beginning of the testing that their responses would be confidential and would not affect their course grades. The pretest survey was given at the beginning of the first laboratory lecture for the experimental group and in the first week of lab at the control school. The posttest was given during the last laboratory period at both schools. All students had twenty minutes to complete each instrument. The twelve chemistry-principles questions and nine of the attitudinal questions were identical on the pretest and posttest. Seventeen additional attitudinal survey items were included in the posttest that would not have been meaningful on the pretest, such as the students’ level of agreement with the statement “Taking this course has increased my interest in science in general.” The attitudinal survey items covered six main topics: usefulness of Web-based computer assignments, increased awareness of chemistry and science as a result of this class, applying chemical principles to the everyday world, ability to mentally see three-dimensional molecular images, usefulness of illustrations, and usefulness of animations. There were three to five items pertaining to each topic. 1874
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School Characteristics The experimental and the control schools are both private, urban institutions that compete for the same students, although the schools are not in the same geographical area. The following data describing the schools were obtained from Peterson’s Guide to Four-year Colleges (14). Verbal SAT scores had a range of 620–710 (experimental school) and 630–710 (control). Mathematics SAT scores were also equivalent, with a range of 650–730 (experimental school) and 650–720 (control school). Both schools have an undergraduate enrollment of about 6000 students. The control school enrolls a slightly higher proportion of women at 54% of undergraduates versus 50% at the experimental school. Both institutions operate prestigious medical schools and many of the undergraduates are premed at both institutions. The primary difference between the institutions is that the control school does not have an engineering college and the experimental school does. Hence, we gave special attention to the effect of the engineers’ responses in the experimental group data. Otherwise, the schools and the students are very similar and comparisons between the two should be valid. In the presentation of the data and results below, Washington University is denoted as WU and the control school is denoted as control. Student Characteristics Only students enrolled in the first semester of chemistry laboratory who completed both a pretest and a posttest were included in this study, and each of these students was defined as a “case.” The number of students included in the study and some of their characteristics are detailed in Table 4. The samples are large, both in terms of absolute number of students (WU, n = 476; control, n = 230), and percent of the class included (WU = 82%, control = 55%). Differences in the level of participation at the two schools may have resulted from the importance placed on recruiting participants at the two institutions. The class compositions were quite similar between schools, except that WU had a greater percentage of engineering students and the control group had a greater percentage of females. Both groups contained similar proportions of first-year and upperclass students.
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Table 4. Student Characteristics
Attitudinal–self-confidence data grouped by topic were treated via summated rating scale (Likert scale) analysis (15, 16). Integer scale values of 1 through 5 were assigned to agreement response choices (strongly disagree = 1, disagree = 2, no opinion–neutral = 3, agree = 4, strongly agree = 5) with reverse scaling employed for negative statements (strongly agree = 1 . . . strongly disagree = 5). The number of cases used for comparisons of the responses to attitudinal questions varies between questions, since not all students gave meaningful answers to every question. In most instances, a response of “Don’t Know” or “Did Not Use” was treated as if no response was given. In those instances where a response of “Did Not Use” was included as a data point, it was treated as “Strongly Disagree.” Internal consistency for the set of questions within each topical area was assessed with the Cronbach’s alpha coefficient. Sets of questions with α > 0.75 were accepted as being internally consistent (17). Group data (both attitudinal–self-confidence data and performance on the chemistry-content questions) are reported as mean ± sem and comparisons between groups were made using an independent-groups analysis of variance (ANOVA). The independent variables are the school (WU or control) and gender. The General Linear Model function in the SPSS program was used to perform the ANOVA calculations (18). Differences between groups were accepted as statistically significant for p values ≤ 0.01.
Number of Students by Gender: School Control WU
Male
Female
Total Casesa
Students in Lab
Students in Study (%)
80
150
230
416
55
230
246
476
582
82
Number of Students by Initial Plan of Study: School Biology Chemistry Engineering Undecided
Other
Control
74 (32%)b
27 (12%)
2 ( 0.75) of five questions were constructed in two of the six attitudinal–self-confidence topical areas. The first set, “increased awareness of chemistry and science as a result of course” consisted of questions concerning student perception of the connections between chemistry and other disciplines, the importance of chemistry in the world around them, and students’ interest in science.1 The second internally consistent set, “usefulness of Web-based computer assignments”, aggregated questions about whether computer assignments improved students’ understanding of the material taught in their chemistry courses and other science courses.2 Since the scale ranges from “strongly disagree” = 1 to “strongly agree” = 5, group means greater than three indicate positive attitudes. Mean responses to both internally consistent sets of questions are compared in Table 5. Experimental group students have more positive attitudes than do the control students about the importance of chemistry in the world around them as indicated by higher means on the “increased awareness of chemistry and science as a result of course” questions (F1,663 = 11.36, p = 0.001). WU responses remain higher even when the students’ response to the statement “Chemistry is not important to daily life” is used as a covariate (F1,660 = 11.81, p = 0.001). Experimental group students have more positive attitudes about their Web-based tutorial computer assignments than the control students do about their Web-based chapter review quizzes as shown by higher group means for “usefulness of Web-based computer assignments” questions www.JCE.DivCHED.org
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Increased Awareness of Chemistry and Science as a Result of Course
Usefulness of Web-based Computer Assignments
0.83
0.87
WU Mean ± sem
3.58 ± 0.03
3.28 ± 0.04
Control Mean ± sem
3.38 ± 0.05
2.91 ± 0.06
F1,663 = 11.36, p = 0.001
F1,553 = 23.37, p < 0.001 3.13 ± 0.05
Variable
Cronbach’s α School Variable:
Statistical results based on the school variable Gender Variable: Female Mean ± sem
3.53 ± 0.04
Male Mean ± sem
3.50 ± 0.04
3.20 ± 0.05
Statistical results based on the gender variable
F1,663 = 0.77, p = 0.38
F1,553 = 0.74, p = 0.40
NOTE: Data based on group of five questions. Individual questions in each internally consistent set are listed in Notes 1 and 2.
(F1,553 = 23.37, p < 0.001). The group means remain statistically significantly different when responses to the statement “I enjoy assignments that require me to use a computer” are used as a covariate (F1,528 = 27.88, p < 0.001). Male and female mean responses to both internally consistent sets of questions are also compared in Table 5. Males and females at both schools are equally aware of the importance of chemistry in the world around them. The ANOVA test provides no evidence that responses differ by gender,
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(F1,663 = 0.77, p = 0.38), nor is there any interaction between school and gender (F1,663 = 0.02, p = 0.89). Males and females at both schools are equally positive about Web-based computer assignments; that is, there is no difference in response by gender (F1,533 = 0.74, p = 0.39). None of the other attitudinal topical groups formed internally reliable aggregates. Therefore comparisons of experimental results to those of the control group will not be made for any other attitudinal question. Nevertheless, it is informative to examine what the responses of the experimental group students are to the other attitudinal questions. A histogram of WU student responses to the remaining attitudinal questions, grouped by topic, is shown in Figure 2. The groups of questions are logical, but do not comprise internally consistent sets. Note that in the “I used the interactive capability” category, students who did not access the interactive materials might circle either “Did Not Use” or “Strongly Disagree.” Therefore, in this category, a response
Figure 2. Experimental group students’ responses to posttest attitudinal questions. The specific questions included in each topical group are listed in Notes 3–6.
Table 6. Content Scores Content Scores by School: WU
Test
Control
Statistical Results
Mean
SEM
Mean
SEM
Pretest
3.42
0.08
3.11
0.10
F
Posttest
4.72
0.09
3.58
0.12 56.01
p
3.926 0.05
